Search

Fatal aviation accidents are a critical concern for armed forces, necessitating precise toxicological analysis of postmortem blood samples. This paper introduces a novel spectrophotometric method for quantifying cyanide in blood samples with an aim to aid in aircraft accident reconstruction in the future. Blood samples were collected from healthy non-smokers aged 20–45 years, excluding individuals with hepatic impairment, or those using drugs affecting blood cyanide levels. The spectrophotometric method involved cyanide adsorption in a sodium hydroxide solution using microdiffusion discs and chemical reactions resulting in a pinkish-purple end product. The optimal absorption wavelength (λ max) was determined, and the lower limits of detection and quantitation were established. The method underwent validation for precision, sensitivity, specificity, linearity, and accuracy. The procedure yielded a pinkish-purple compound with an optimal absorption wavelength (λ max) of 531 nm. The established limits of detection (LoD) and quantitation (LoQ) were 0.0625 μg/ml and 0.125 μg/ml, respectively. The method demonstrated strong linearity up to cyanide concentrations of 4 μg/ml. It exhibited a sensitivity of 99.7% and accuracy of 85.92%. The intraday and inter-day precision were determined as 9.04% and 4.27%, respectively. The method was highly specific, showing no interference with blanks at the peak wavelength with a working range of 0.125–4 μg/ml. The study describes developing and validating a sensitive method for quantitatively estimating cyanide in blood samples. Incorporating this method into the existing postmortem toxicological sample collection and investigation protocol will enhance the analysis capabilities and improve aircraft accident investigation outcomes within the country. [ABSTRACT FROM AUTHOR]

Owing to improvement of the molecular diagnostic methods using purified preparations of nucleic acids (NAs), the development of effective methods providing the isolation of DNA is still relevant. The sorption properties of magnetic multi-walled carbon nanotubes (MWCNTs), oxidized MWCNTs and MWCNTs (pristine and oxidized) modified with polydiallyldimethylammonium chloride (pDADMAC) with respect to double strained DNA have been studied. It was shown that in the presence of MWCNTs/pDADMAC particles the DNA molecules were reversibly retained by the particle's surface. The optimal conditions for each step of DNA extraction from model solutions using the obtained material were selected. A comparative evaluation of the effectiveness of the proposed method for DNA isolation based on the results of spectrophotometry and real-time PCR was carried out. It was shown that the desorbed DNA was efficiently amplified in PCR, inhibition of polymerase did not occurred. Probable mechanisms of DNA retention due to the influence of residual impurities of catalysts in the MWCNT composition, as well as the surface charge of nanotubes are proposed. Sequentially oxidized and coated with pDADMAC magnetically susceptible CNTs are seemed to be a promising material for development of low-cost systems proving an easy isolation, storage, and subsequent use of ds DNA in molecular diagnostics. The sorption properties of such systems are determined with highly developed specific surface area and their chemical composition. • Sequentially oxidized and modified with polycations magnetic multi-walled carbon nanotubes reversibly retain ds DNA. • The desorbed DNA is efficiently amplified in PCR, inhibition of polymerase is not observed. • The spectrophotometrically determined value of the DNA yield coincides with the value determined by PCR-analysis. [ABSTRACT FROM AUTHOR]

Imaging spectrometry is a powerful tool among remote sensing techniques to analyze the chemical compositions and physical properties of the lunar regolith. Recalibration of the classical method byLucey and co-workers with Moon Mineralogy Mapper (M3) data provides an opportunity to understand the FeO, TiO 2, and optical maturity distributions over the lunar nearside on a global scale. We estimated the chemical compositionsand optical maturity from the M3 spectral reflectance around the 1 µm region. The standard chemical compositions of the lunar landing sites were estimated based on origin optimization and data fitting. We obtained an optimized origin of (0.08, 1.18) for FeO and (0.07, 0.71) for TiO 2. The Spectrophotometric evaluations of Catharina and Cyrillus craters, located in the lunar nearside are categorized under the matured category. The estimation results reveal that the FeO wt % of the Catharina crater varies from 0.0002 to 19.62, and that of the Cyrillus crater varies from 0.0001 to 12.32. TiO 2 wt% of Catharina crater varies from 0.01 to 86.12, while Cyrillus Crater varies from 0.01 to 4.34. The optical maturity (OMAT) of the Catharina crater varies from 0.0001 to 0.19 to that of the Cyrillus Crater Varies from 0.01 to 0.17. The overall summary of the results points out that lunar regolith is a fabulous repository of FeO and TiO 2 and quantitatively this metal abundance may be more than the anticipated values. [ABSTRACT FROM AUTHOR]

Our in vitro comparative study aimed to investigate the impact of thickness and tooth shade background on the translucency of highly translucent zirconia veneers. A total of 75 5Y-TZP zirconia veneers of shade A1 were fabricated with thicknesses of 0.50 mm (n = 25), 0.75 mm (n = 25), and 1.0 mm (n = 25). The translucencies were measured on composite resin teeth with shades A1, A2, A3, A3.5, and A4 using a digital color imaging spectrophotometer. Data were analyzed using ANOVA and post hoc Tukey's test (p < 0.05). The translucency values were optimal for the veneers placed over the substrate teeth with shades A1 and A2, regardless of the veneer thickness. Additionally, veneers with a thickness of 0.50 mm exhibited significantly higher translucency than those with thicknesses of 0.75 mm and 1.0 mm. Our study demonstrated that the translucency of the highly translucent zirconia veneers was influenced by both veneer thickness and tooth shade background. The optimal veneer thickness for achieving the highest translucency was 0.50 for the veneers with A1 and A2 shades placed over the substrate teeth. The optimal thickness for achieving the highest translucency of the highly translucent zirconia laminate veneers was 0.50 mm for the veneers with A1 and A2 shades placed over the substrate teeth. Clinicians and dental technicians could consider this when selecting materials for aesthetic restorations. [ABSTRACT FROM AUTHOR]

The objective of this study was to determine whether seated cervical manipulation produced changes in autonomic nervous system activity, as measured by heart rate variability and plasma norepinephrine levels. Ninety-five healthy young adults (ages 20-48 years) were recruited into a single-blinded physiological study, with 47 randomized to a seated cervical manipulation and 44 randomized to a sham procedure. Heart rate variability in the frequency domain, and plasma norepinephrine levels were measured prior to, immediately following, and 5 minutes following the intervention. Electrocardiograms were obtained from 39 subjects in the sham group and 43 subjects in the manipulation group. No statistically significant changes were found in measures of heart rate variability in the frequency domain in either the manipulation or sham groups. Blood samples were obtained from 22 subjects in the sham group and 27 subjects in the manipulation group. Plasma norepinephrine levels, as measured by spectrophotometry, declined in both groups from pre- to immediately postintervention, and they remained at decreased levels 5 minutes after the interventions. There were no statistically significant differences between groups in pre- or postintervention norepinephrine levels. Measures of heart rate variability and plasma norepinephrine levels did not show that seated cervical manipulation produced short-term changes in autonomic nervous system activity compared to a sham procedure in healthy young adults. [ABSTRACT FROM AUTHOR]

Spectrophotometers or optical benches using integrating spheres to measure normal-hemispherical transmittance T N H are widespread laboratory equipments. Although it is known that they cannot be used for "highly turbid" samples, because multiple scattering may lead transmitted radiation to miss the entrance of the integrating sphere, very little is generally known about their exact validity range. Here we present a method to characterize the validity range of any such spectrophotometer and observe that most of them fail to measure T N H for scattering optical thickness above 0.25 (i.e. for T N H < 0. 9 in the case of non absorbing media with g = 0). We also show how it is possible to continue using spectrophotometers even outside their T N H measurement validity range, without any calibration, thanks to a proper simulation of radiative transfer and geometrical optics. We make available the corresponding radiative transfer simulation tools as open access codes, that have been developed for a straightforward implementation on a wide range of experimental setups. The method is validated on three different spectrophotometers or optical benches using standardized latex microspheres, then its practical implementation is illustrated in the case of semi-conductor particles and photosynthetic microalgae. Errors in analysis arising from the misuse of such optical devices are discussed throughout the article. [Display omitted] • We study TNH measurements with standard optical benches and spectrophotometers. • For turbid samples, the finite size of the sensor prevents from measuring the TNH. • We assess the validity range where the experimental signal matches the TNH. • An accurate model of the optical bench enables to use it beyond its validity range. • We provide open-access tools to compute this model on any optical bench. [ABSTRACT FROM AUTHOR]

[Display omitted] • Simple and accurate spectrophotometric method for the determination of celecoxib and tramadol. • Principle component regression chemometric model was applied. • The model optimized and validated. Celecoxib and tramadol have been combined in a novel FDA-approved medication to address acute pain disorders requiring opioid treatment when other analgesics proved either intolerable or ineffective. The absorbance spectra of celecoxib and tramadol exhibit significant overlap, posing challenges for their individual quantification. This study introduces a spectrophotometric quantification approach for celecoxib and tramadol using a principle component regression assistive model to assist resolving the overlapped spectra and quantifying both drugs in their binary mixture. The model was constructed by establishing calibration and validation sets for the celecoxib and tramadol mixture, employing a five-level, two-factor experimental design, resulting in 25 samples. Spectral data from these mixtures were measured and preprocessed to eliminate noise in the 200–210 nm range and zero absorbance values in the 290–400 nm range. Consequently, the dataset was streamlined to 81 variables. The predicted concentrations were compared with the known concentrations of celecoxib and tramadol, and the errors in the predictions were evidenced calculating root mean square error of cross-validation and root mean square error of prediction. Validation results demonstrate the efficacy of the models in predicting outcomes; recovery rates approaching 100 % are demonstrated with relative root mean square error of prediction (RRMSEP) values of 0.052 and 0.164 for tramadol and celecoxib, respectively. The selectivity was further evaluated by quantifying celecoxib and tramadol in the presence of potentially interfering drugs. The model demonstrated success in quantifying celecoxib and tramadol in laboratory-prepared tablets, producing metrics consistent with those reported in previously established spectrophotometric methods. [ABSTRACT FROM AUTHOR]

[Display omitted] • Contraceptives drug containing ethinyl estradiol and drospirenone were determined simultaneously. • Rapid, low-cost, accurate, and without prior separation step methods (CWT, DWT + FIS) along with spectrophotometry were used. • The other benefit of the proposed methods is without the use of additional solvents polluting the environment. • These methods were implemented on synthetic mixtures and real sample. • HPLC technique was compared to UV-spectrophotometric method using the ANOVA test. In this study, the spectrophotometric method integrated with continuous wavelet transform (CWT) and coupled discrete wavelet transform (DWT) with fuzzy inference system (FIS) was developed for the simultaneous determination of ethinyl estradiol (EE) and drospirenone (DP) in combined oral contraceptives (COCs). The CWT approach was performed in the linearity range of 0.6–6 µg/mL for EE and 0.9 to 18 µg/mL for DP. Biorthogonal with an order of 1.3 (bior1.3) at a wavelength of 216 nm and Daubechies with an order of 2 (db2) at a wavelength of 278 nm were selected as the best wavelet families for obtaining the best zero crossing point for EE and DP, respectively. The limit of detection (LOD) of 0.7677 and 0.3222 µg/mL and the limit of quantification (LOQ) of 2.326 and 0.9765 µg/mL were obtained for EE and DP, respectively. The mean recovery of 103.24% and 99.77%, as well as root mean square error (RMSE) of 0.1896 and 0.1969, were found for EE and DP, respectively. In the DWT, the absorption of the mixtures was decomposed using different wavelets named db4, db2, Symlet2 (sym2), and bior1.3. Each of the wavelet outputs was dimension reduced by the principal component analysis (PCA) method and considered as FIS input. The wavelet of db4 with the coefficient of determination (R2) of 0.9979, RMSE of 0.0968, and mean recovery of 100.63% was chosen as the best one for the EE, while bior1.3 with R2 of 0.9955, RMSE of 0.4055, and mean recovery of 101.93% was selected for DP. These methods were successfully used to analyze the EE and DP simultaneously in tablet pharmaceutical formulation without any separation step. The suggested methods were compared with a reference method (HPLC) using analysis of variance (ANOVA) at a 95% confidence level, and no significant difference was observed in terms of accuracy. The suggested chemometric methods are reliable, rapid, and inexpensive, and can be used as an environmentally friendly alternative to HPLC for the simultaneous estimation of the mentioned drugs in commercial pharmaceutical products. [ABSTRACT FROM AUTHOR]

[Display omitted] • Pencil graphide electrode was employed for the first time for determination of ribociclib. • The most important advantages of the voltammetric method: simple and environmentally friendly. • Successful application of the developed voltammetric technique in pharmaceutical and urine samples. • Investigation of ribociclib-DNA interaction by voltammetric, spectroscopic and molecular docking techniques. Ribociclib (RIB) is a cyclin-dependent kinase inhibitor used in the treatment of breast cancer. In this study, for the first time, the electrochemical behavior, quantification and interaction of RIB with DNA were carried out using voltammetric, spectrophotometric and molecular docking techniques. An environmentally-friendly disposable pencil graphite electrode (PGE) sensor was used as the working electrode. Utilizing the cyclic voltammetry technique, RIB produced an irreversible anodic wave around +0.837 V and reversible signals around +0.278 V/+0.209 V on the PGE surface. Using the PGE sensor, the RIB compound gave a very distinct anodic signal at a potential of +0.77 V in PBS (pH 3.0). For this analytical signal, the limit of detection and limit of quantitation values of RIB in the concentration range of 0.0139 3 M–0.0973 3 M in PBS (pH 3.0) were determined as 2.84 nM and 9.46 nM, respectively. The interaction of RIB with DNA was studied by voltammetric, spectrophotometric and molecular docking techniques. In the evaluation of the results obtained with all three techniques, the interaction of the RIB molecule with DNA was determined to occur through minor groove binding. [ABSTRACT FROM AUTHOR]

An alloy-based fuel comprised of U-Pu-Zr is under development for the futuristic fast reactors to improve fissile atom utilization. As the technical data available with the metal fuel reactors is limited, it is imperative to have an exhaustive comprehension of behavior of fission and activation products before deploying the U-Pu-Zr metal fuel for commercial applications. Towards meeting this objective, the present paper highlights the analytical estimation of Zr and Am in the irradiated U-Zr metal that has experienced a low burn-up. The estimation of Zr was carried out by a modified spectrophotometric method developed in our laboratory. The estimation of Am was accomplished through initial liquid-liquid extraction-based removal of U and Pu by tri- n ‑butyl phosphate followed by the separation of Am by TODGA from the raffinate. Am was estimated with the help of alpha spectrometry of the Am-separated TODGA phase, and the same has been substantiated by comparing it with the results of gamma spectrometry. [ABSTRACT FROM AUTHOR]

[Display omitted] • Curcumin, resveratrol, and quercetin have been determined by new spectroscopic methods. • Selective determination of the ternary mixture with severe spectral overlap has been carried out. • The methods depend on avoiding hazardous solvents. • Different validation parameters were tested and approved. • The greenness and whiteness of the proposed methods were assessed. The combination of Curcumin (CRN), resveratrol (RSV), and quercetin (QRN) has significant antioxidant effects and is found to be more effective than a single polyphenol. Spectrophotometric methods are considered one of the most common analytical techniques for the determination of the drugs due to their sensitivity, rapidness, low cost, and reproducibility. Therefore, the presence of new, and simple methods for the determination of such compounds will be highly valuable, specially in the presence of spectral overlap. In this research, five different facile spectrophotometric methods were investigated for the simultaneous determination of that ternary mixture for the first time, including zero order (I), first derivative (II), ratio difference double divisor (III), first derivative ratio spectra (IV), and mean centering (V) methods. The designed approaches were linear over the concentration ranges of (1.0–10.0), (0.5–8.0), and (1.0–14.0) μg/mL, respectively for curcumin, resveratrol, and quercetin. The different methods were then validated as stated by the International Council of Harmonization. The accuracy and precision have been evaluated by statistical analysis including student t -test, variance ratio F-test, and ANOVA. Moreover, the greenness and whiteness of the proposed methods were assessed to ensure the adherence to the greenness characters. [ABSTRACT FROM AUTHOR]

Traditional harvest of Achyrocline satureioides (AS) occurs at dawn on Good Friday in some South American countries. Inflorescences are traditionally used as infusions for several disorders, including neuropsychiatric disorders. Pillows and cushions are popularly filled with AS to attenuate the symptoms of depression, anxiety, and sleep disturbances. However, evidence for the potential beneficial effects of AS on human neural cells remains unclear. An in vitro model of SH-SY5Y human neural cells was applied to evaluate the effect of AS infusion, prepared as commonly used, on cells exposed to rotenone and to investigate its potential for neuropsychiatric disorders. A hot aqueous extract was obtained from a traditionally prepared AS inflorescence infusion and chemically characterized by high-resolution mass spectrometry and spectrophotometric quantification of total polyphenols, tannins, and flavonoids. The SH-SY5Y cell cultures were treated with AS extract at concentrations of 1, 3, 5, 10, 50, 100, and 300 μL/mL to determine the potential cyto- and genotoxic effects of AS on neural cells using MTT, Neutral Red, and GEMO assays. Apoptosis modulation was assessed using flow cytometry and apoptosis-modulating genes were evaluated by qRT-PCR. The protective effect of AS on the neurotoxicity triggered by rotenone exposure (30 nM) was determined by analyzing cellular viability and oxidative markers such as lipid peroxidation and protein carbonylation, and DNA damage was assessed by micronucleus assay. The AS extract, as traditionally prepared, had estimated concentrations of 409.973 ± 31.107 μg/mL, 0.1041 ± 0.0246 mg GAE/mL, and 63.309 ± 3.178 mg QE/mL of total tannins, total polyphenols, and flavonoids, respectively. At concentrations of 30 and 100 μl/mL, AS decreased apoptotic events, whereas the highest concentration (300 μl/mL) increased apoptosis compared to that in the control (p < 0.05). In cells exposed to rotenone, AS treatment induced cell proliferation, reduced DNA damage (as evaluated by micronuclei), and reduced lipid and protein oxidation. The data indicate the non-cytotoxic and beneficial effects of AS extract on human neural cells by reducing cellular mortality and oxidative stress in neural cells triggered by rotenone exposure. [Display omitted] • Achyrocline satureioides protects neural cells from rotenone-induced damage. • Achyrocline satureioides reduces oxidative stress in human neural cells. • Achyrocline satureioides induces neuroproliferative activity. [ABSTRACT FROM AUTHOR]

In the search of innovative methods within radiation dosimetry to provide solutions to the high demanding modern ionizing radiation applications, this work proposes an original approach to combine microorganisms and gel dosimetry characteristics by adapting biotechnology and molecular biology procedures. The design of bacterial culture media and the evaluation of viability as systems for radiation dosimetry are reported. In preliminary assessments, a highly promising dose-response has been observed for samples stored at 4 °C, displaying a linear trend within the investigated dose range. This underscores a promising performance, indicating the potential utility of the system as a radiation dosimeter. • A novel dosimeter integrating gelatin matrices with micro-organisms is presented. • Sample preparation along with their suitability for spectrophotometry analysis are described. • Agarose addition providing nutrients has negligible effects on sample's optical properties. • Successful bacterial growth is demonstrated using Staphylococcus-aureus strains. • High linear correlation is proven for the dose-response in the 0.5–3 Gy dose range. [ABSTRACT FROM AUTHOR]

40 nm thick La 2 / 3 Sr 1 / 3 MnO 3 (LSMO) thin films were epitaxially grown by Pulsed Laser Deposition (PLD) onto niobium doped SrTiO 3 (Nb:STO) substrates, with different Nb concentration from 0.01%wt to 0.5%wt. The optical characterization of the heterostructures by spectroscopic ellipsometry enables us to extract the optical constants of the manganite heteroepitaxial layer at room temperature. Performing spectrophotometry in the same wavelength range brings a useful cross-validation of the extracted results. In addition, the thickness evaluation of the LSMO layer by spectro-ellipsometry is further validated by both High Resolution X-ray diffraction and X-ray reflectivity, as well as a Transmission Electron Microscopy cross section, taken as a physical reference. This study validates quantitatively the spectro-ellipsometry as a suitable routine tool to measure accurately both thickness and complex refractive index of the LSMO thin film, picturing their peculiar electrical behaviour between both metallic and insulating phases. The relative error on the thickness measurement between X-ray and ellipsometry is less than 5%. The LSMO complex refractive index enabled also a simultaneous estimation of further material properties, such as the optical gap ω g or the mass density ρ m , determined with less than 1.5% relative error compared to X-ray reflectivity results. [Display omitted] • Physically-based accurate ellipsometric modelling of heteroepitaxial manganite. • Simultaneous estimation of LSMO thickness, roughness, mass density and optical gap. • Quantitative matching between X-ray and optical techniques on thin film. [ABSTRACT FROM AUTHOR]

Spectral differences in ambient light can affect animal behavior and convey crucial information about an individual's environment. The ability to perceive and respond to differences in ambient light varies widely by taxa and is shaped by a species' ecology. Mexican jumping bean moths, Cydia saltitans , spend their entire larval period encased in fallen host seeds and contend with potentially lethal environmental temperatures when host seeds are in direct sunlight. We investigate if and how C. saltitans larvae in host seeds respond to lighting conditions associated with these thermal risks. In a temperature-controlled experiment, we identified that larvae demonstrated distinct behavioral ("jumping") responses corresponding to four lighting treatments (white, red, green, and purple), despite extremely minimal light penetration through host seed walls. Red light induced the greatest larval activity (measured by probability of movement and by displacement from origin), suggesting that larvae have mechanisms to perceive low levels of red light and/or to detect subtle increases in heat produced by red/near infrared-biased light spectra, possibly providing them with an early-warning mechanism against thermal stress. Our findings highlight the interplay of environmental lighting, behavior, and potential thermosensory adaptations in a species with a visually constrained environment. • Spectral differences in ambient light can be informative and alter behavior. • Cydia saltitans larvae use host seeds and jump to avoid sunlight-associated heat. • We tested if larvae responded to variation in ambient light spectra. • Although little light penetrated the host seed, light altered larval behavior. • To avoid high heat, larvae may have specialized light-related sensory adaptations. [ABSTRACT FROM AUTHOR]

In this work, a novel sensitive composition of Fricke radio-chromic gel dosimeter based on polyvinyl alcohol (PVA), xylenol orange (XO), and physical cross-linking agent gellan gum (GG) is presented and evaluated with two optically detection methods. The Fricke dosimeter was irradiated up to 30Gy using medical linear accelerator and analyzed optically using ultraviolet visible (UV–Vis) spectrophotometry technique at wavelengths of 585 nm (i.e., within the visible range) and two-dimensional optical imaging system of charge-coupled-device (CCD) camera with a uniform red light-emitting-diode (LED) array source. The Fricke dosimeter demonstrated important properties including independence of beam energy and dose rate over the range studied. In addition, these dosimeters have high sensitivity in the range of 0–10Gy, and significant low diffusion coefficient of 0.070 mm2 h−1. In addition, the composition shows a lower diffusion coefficient with respect to those reported so far for a Fricke dosimeter. The total uncertainty of the estimated doses for the Fricke dosimeter was 3.96% at 95% confidence level. • Fricke XO-PVA dosimeter with physical gellan gum cross-linker was studied with two optical read-out techniques. • The dosimeter sensitivity was higher than other Fricke XO-PVA and gelatin-based gel dosimeters reported previously. • The dosimeter shows a lower diffusion coefficient with respect to those reported so far for a Fricke dosimeter. • The total uncertainty of the estimated doses for the Fricke dosimeters was found to be and 3.96% at 95% confidence level. [ABSTRACT FROM AUTHOR]

We introduce a novel method, namely IrRAC, for assessing total antioxidant capacity utilizing the single electron oxidant hexachloroiridate(IV). This method leverages the 488 nm absorption band of [IrCl 6 ]2− largely reducing interferences from antioxidants and their oxidation products. [IrCl 6 ]2− is stable 6 h in phosphate-buffered saline (PBS) ensuring consistent and reproducible absorbance readings and rendering spectrophotometric determinations under physiological neutrality. Individual assessments of 23 antioxidants reveal a linear correlation between decreasing absorbance and increasing antioxidant concentration. When the IrRAC assay was compared with several established water-based methods, strong correlations were found. Importantly, [IrCl 6 ]2− shows a minimal oxidation of non-antioxidative substances. Moreover, IrRAC performs well with synthetic antioxidant mixtures and real samples, highlighting that the nature of antioxidants dominates the assay without much disturbance. Commercial availability of K 2 [IrCl 6 ] eliminates the need of pretreatment of the oxidant. Undoubtedly, the new method confers a compelling and cost-effective alternative to the existing electron transfer-based methodologies. • A novel method IrRAC for assessing total antioxidant capacity was developed. • Direct use of commercially available Ir(IV) reagent eliminates extra peparations. • The used absorption band around 488 nm of Ir(IV) minimizes interferencs. • IrRAC is strongly correlated with other relavent methods validating its reliability. • Wide applications to the TAC analysis of pure and real samples are anticipated. [ABSTRACT FROM AUTHOR]

Background: Deuterium oxide (D2O) dilution is the criterion method for total body water (TBW) measurement, but results may vary depending on the specimen type, analysis method, and analyzing laboratory. Bioelectrical impedance (BIA) estimates TBW, but results may vary by device make and model.Objectives: We investigated the accuracy and precision of TBW estimates and how measurement conditions affected the accuracy of body composition using multicompartment body composition models.Methods: Eighty collegiate athletes received duplicate TBW measures acquired from 3 BIA devices (S10, SFB7, and SOZO) and from unique D2O combinations of specimen type (saliva, urine), analysis methodology [Fourier transform infrared spectrophotometry (FTIR), isotope-ratio mass spectrometry (IRMS)], and 3 different laboratories. TBW measures were substituted into 2-compartment (2C) and 5-compartment (5C) body composition models. Criterion measures were compared using Lin's concordance correlation coefficient cutoff of poor (<0.90), moderate (0.90-0.95), substantial (0.95-0.99), and almost perfect (>0.99).Results: Fifty-one participants (26 female) completed the protocol. Using IRMS saliva as the criterion TBW, all other measures produced a substantial or almost perfect agreement, except for SFB7 (poor) and SOZO (moderate). The 2C body composition measures using D2O and BIA produced poor agreement except for moderate agreement for lab 3 FTIR saliva. The 5C body composition measures using D2O produced a substantial agreement, whereas the BIA device S10 and SOZO had a moderate agreement, while the SFB7 had a poor agreement to the criterion. Test-retest precision varied between techniques from 0.3% to 1.2% for TBW.Conclusions: Small differences in TBW measurement led to significant differences in 2C models. The 5C models partially mitigate differences seen in 2C models when different TBW measures are used. Interchanging TBW measures in multicompartment models can be problematic and should be performed with these considerations. [ABSTRACT FROM AUTHOR]

• First report on high cytokinin-induced hyperhydricity in gerbera. • Hyperhydricity resulted in delayed and poor regeneration, lower chlorophyll and higher relative water content. • Leaf folding, lower frequency and size of stomata, along with thinner, shorter and fewer roots observed in hyperhydric plants. • Identified key traits can be utilized to screen the hyperhydric plantlets at an early stage of growth for necessary remediation. Gerbera (Gerbera jamesonii Bolus) ranks amid the top five commercially preferred cut-flowers in global floriculture industry. Conventionally, gerbera is propagated by seed or by vegetative approaches. However, in vitro propagation cropped up as a better alternative with high commercial success since past two decades. Simultaneously, hyperhydricity of shoots has become a matter of serious concern during in vitro propagation. For the first time in gerbera, the present study highlights the morphometrical and physiological changes in hyperhydric shoots developed in high cytokinin-supplemented media. Four concentrations (2.5, 5, 7.5 and 10 mg L −1) of kinetin and N6-benzylaminopurine (BAP) were tested individually in supplementation with Murashige and Skoog basal medium. It was found that occurrence of hyperhydricity was significantly influenced by the type and concentrations of cytokinins used. Nevertheless, gradually increasing hyperhydricity along with significantly poorer multiplication were observed with the increasing concentrations of BAP and kinetin compared to its lower levels. Majority of explants in the presence of high levels (> 5 mg L −1) of kinetin or BAP became hyperhydric, losing their capability to regenerate. Hyperhydric plantlets exhibited lower chlorophyll and higher relative water content, resulting in glassy appearance of leaves and shoots with pale or yellowish green color accompanied with inward folding of the leaf blade towards the midrib. The roots of hyperhydric plantlets were thinner, shorter and fewer in number. Hyperhydricity further resulted in delayed development of plantlets as well as lower frequency and size of stomata. [ABSTRACT FROM AUTHOR]

The mining of extra-thick coal seams features severe deformation of the stoping roadway and section coal pillars due to the large mining thickness of the coal seams and the intense movement of the overlying strata. The adjacent goaf and secondary mining disturbance in the current working face further challenge the roadway deformation control. This study explores the effect of the overlying strata structural evolution in the fully mechanized caving face of the extra-thick seam on the failure of section roadway and coal pillars. Physical analog modeling was carried out. A MatchID non-contact full-field displacement- and strain-measuring system was used to determine the evolutionary characteristics of the overlying strata breakage in the extra-thick coal seam, including the displacement variation pattern and stress/strain distribution in coal pillars. The results indicated that following the primary mining disturbance in the adjacent working face, the section roadway and coal pillars underwent initial deformation due to the primary mining-induced stress. As the mining of the current working face continued, the section roadway and coal pillars were subjected to secondary mining disturbance to the effect that the structure of the broken overlying strata gradually formed a triangular support structure. Thus, the overlying strata tilted downwards and subsided, forming a layered hanging roof structure. The additional load was then imposed on the stoping roadway and upper part of the section coal pillars. Meanwhile, the overlying strata failure caused a significant increase in the stress within the section coal pillars. Following the secondary mining disturbance, the peak stress reached a maximum of 33.62 KPa, leading to deformation and instability failure of the section roadway and coal pillars. Finally, distinctive evolutionary features of the overlying strata structure in the extra-thick and ordinary coal seams were identified, and their effect on the deformation and failure of the section roadway and coal pillars were analyzed in detail. These findings are considered instrumental in substantiating the deformation control of the stoping roadway and coal pillars in the extra-thick coal seams. [ABSTRACT FROM AUTHOR]

Ion pair-based surfactant-assisted liquid-liquid microextraction with solidification of floating organic drops has been developed to extract Allura red (AR), tartrazine (TAR), and fast green (FG) prior to spectrophotometric determination. Cetyltrimethylammonium bromide (CTAB) was employed as ion-pairing agent to enhance the hydrophobic behavior of anionic dyes. 1-undecanol and ethanol were used as the extraction and dispersion solvents, respectively. The dyes were quantitatively extracted in the presence of KCl (0.15 mol L−1) at pH 4.0. The method exhibits wide linearity (15.0–1500.0 μg L−1 for AR, 35.0–2000.0 μg L−1 for TAR, and 3.0–1200.0 μg L−1 for FG) with preconcentration factors of 19.6, 20.1, and 19.9, respectively. The detection limit was 3.7. 9.5, and 0.83 μg L−1 for AR, TAR, and FG, respectively. The relative standard deviation did not exceed 2.1 %. The procedure was applied for the determination of these dyes in food samples. [Display omitted] • An efficient IP-SA-DLLME-SFOD procedure was developed for anionic dyes. • The extraction was induced by salt addition (0.15 mol L−1 of KCl). • Simple and accurate extraction at room temperature in 10.0 min. • The extraction recoveries were 95.0-100.0 %. • Applied for spectrophotometric determination of dyes in food samples. [ABSTRACT FROM AUTHOR]

[Display omitted] • Two spectroscopic methods were reported for olanzapine assay using erythrosine B as a probe. • The procedure does not include complex steps in sample preparation, extraction or heating. • The suggested methods were applied to analyze tablets formulation and spiked human plasma. • Moreover, the greenness of the procedures was confirmed with two analytical metric tools. In this work, the xanthene dye, erythrosine B, was employed as a probe for the determination of olanzapine using two fast and highly simple analytical approaches. The assay was based on the formation of a binary complex between the drug and erythrosine B in a slightly acidic aqueous buffered solution. In the first method, the absorbance of the formed product was monitored at 558 nm. The reaction stoichiometry was investigated, and the stability constant of the formed complex was estimated. The linear range of the method that obeyed Beer's law was in the concentration range of 0.6–8.0 µg/ml. The calculated detection and quantitation limits were 0.2 and 0.6 µg/mL. Upon adding the drug solution to erythrosine B, the native fluorescence of the dye was quenched and monitored at 550 nm after excitation at 528 nm. Thus, the fluorescence quenching was utilized as the quantitative signal in the spectrofluorimetric approach. The extent of quenching in the fluorescence intensity was rectilinear with the drug concentration in a range of 0.1–2.5 µg/ml with a detection limit of 0.032 µg/ml. Both approaches were analytically validated based on the guiding rules of the ICH with acceptable results, and were utilized efficiently in the analysis of olanzapine in commercial tablets containing the cited drug. In addition, owing to its high sensitivity and selectivity, the spectrofluorimetric method was applied for drug analysis in spiked human plasma with satisfactory % recoveries. Finally, the greenness of the methods was confirmed using eco-score scale and Analytical Green Evaluation metrics. [ABSTRACT FROM AUTHOR]

Representative diagram for the proposed procedure for CPE. [Display omitted] • Complex of As(V) with astrazon orange G using tartaric acid and Triton X-114 is formed. • Cloud-point extraction method to determine arsenic species was described. • The sensitivity, detection, and quantification limits are calculated. • The method is validated by analysis of real samples. A novel cloud-point extraction (CPE) procedure for the determination of ultra-trace amounts of arsenic species in real samples, purchased from the local market by spectrophotometer was developed. Inorganic arsenic species analysis in water, beverages, and foods has become increasingly important in recent years, as arsenic species are considered carcinogenic and are assessed at significant levels in samples. The technique is established on a selective ternary complex of As(V) with astrazon orange G (AOG+) in the presence of tartaric acid and polyethylene glycol tertoctylphenyl ether (Triton X-114) at pH 4.0. The calibration curve developed within range 3.0–160 ng/mL with a correlation coefficient of 0.9988 for As(V) provided a preconcentration factor of 200 and a limit of detection (3S blank/m) of 0.88 ng/mL under optimum investigation conditions. The results of molar absorptivity and Sandell sensitivity are calculated and found to be 4.38 × 105 L/mol cm and 0.018 ng cm−2, respectively. The statistical treatment of data obtained from the proposed and GF-AAS procedures are compared in terms of Student's t-tests and variance ratio F-tests has revealed no significant differences. The methodology has been effectively confirmed by assessing real samples and comparing it to the GF-AAS method statistically. [ABSTRACT FROM AUTHOR]

Acute coronary syndrome (ACS) represents a group of diseases that are the result of reduced blood flow to the heart. There are natural products, based on mushrooms, used traditionally in the treatment of cardiovascular diseases. Assessment of the potential protective effect of L. betulinus mushroom against therapy-induced DNA damage in lymphocytes of patients with ACS in relation to the phytochemical properties of the mushroom. The study included 30 ACS patients and 30 healthy controls. The genotoxic potential of acetone and ethanol extract of L. betulinus was evaluated using the comet assay. The contents of minerals were determined by inductively coupled plasma optical emission spectrometry. Determination of sugars and organic acids was performed using a DIONEX ICS 3000 DP liquid chromatography system. Analysis of fatty acids was performed at Focus GC coupled with PolarisQ mass spectrometer. The total phenolic and flavonoid contents in the mushroom extracts were measured using spectrophotometric methods. The qualitative and quantitative content of polyphenolic compounds was investigated by the UHPLC-DADMS/MS method. The comet assay showed that both mushroom extracts did not increase the level of DNA damage in the lymphocytes of healthy individuals, while they significantly decreased the %DNA damage and genetic damage index (p < 0.0005) in the therapy-induced lymphocytes of patients. The mushroom was very rich in phytochemical composition. The results showed that the most abundant components in the mushroom were phosphorus, potassium, sodium, sulfur, and calcium among minerals and glucose, fructose, galactose, sorbitol, and turanose among carbohydrates. Among organic acids were present in higher concentrations malic, citric, and maleic acids, while among fatty acids, the most abundant were trans-linoleic, cis-oleic, palmitic, docosahexaenoic and eicosadienoic acids. The results showed that the highest amount of total phenols and flavonoids in the mushroom extracts were obtained in the acetone extract. The most abundant polyphenolic compounds were chlorogenic acid and quercetin in both extracts of mushroom. This study indicates that L. betulinus can be considered a mushroom with a high nutritional and functional value. Extracts of the mushroom were not genotoxic in tested concentrations in cultured human lymphocytes of healthy individuals, while in ACS patients they manifested a protective effect against therapy-induced DNA damage. The acetone extract showed a stronger protective effect against therapy-induced DNA damage, which is consistent with its phytochemical composition. [Display omitted] [ABSTRACT FROM AUTHOR]

Manilkara zapota (L.) P. Royen , also termed sapodilla or chikoo, is a significant plant in ethnomedicine because of its long history of traditional medical applications. In diverse cultures, sapodilla is believed to protect against oxidative stress, inflammation, and some chronic diseases because of its high antioxidant content. The naturally occurring antioxidant myricitrin (MYR) flavonoid is primarily found in the leaves and other plant parts of sapodilla and it is well-known for having therapeutic qualities and possible health advantages. To appraise the possible impact of MYR on a rat model of reserpine-induced fibromyalgia (FM) and explore its mechanism of action. Isolation and identification of MYR with more than 99% purity from Manilkara zapota leaves were primarily done and confirmed through chromatographic and spectrophotometric techniques. To develop FM model, reserpine (RSP) was injected daily (1 mg/kg, s.c.) for three successive days. Then, MYR (10 mg/kg, i.p.) and pregabalin (PGB, 30 mg/kg, p.o.) were given daily for another five days. Behavioral changes were assessed through open field test (OFT), hot plate test, and forced swimming test (FST). Further analyses of different brain parameters and signaling pathways were performed to assess monoamines levels, oxidative stress, inflammatory response, apoptotic changes as well as silent information regulator 1 (SIRT1) and micro RNAs (miRNAs) expressions. From High-Performance Liquid Chromatography (HPLC) analysis, the methanol extract of sapodilla leaves contains 166.17 μg/ml of MYR. Results of behavioral tests showed a significant improvement in RSP-induced nociceptive stimulation, reduced locomotion and exploration and depressive-like behavior by MYR. Biochemical analyses showed that MYR significantly ameliorated the RSP-induced imbalance in brain monoamine neurotransmitters. In addition, MYR significantly attenuated oxidative stress elicited by RSP via up-regulating nuclear factor erythroid 2-related factor 2 (Nrf2) and heme oxygenase-1 (HO-1) protein expressions, enhancing superoxide dismutase (SOD) and catalase (CAT) activities, and reducing malondialdehyde (MDA) content in brain. The RSP-provoked inflammatory response was also diminished by MYR treatment as shown by a significant decreased NOD-like receptor protein 3 (NLRP3) inflammasome expression along with reduced levels of interleukin 1 beta (IL-1β) and nuclear factor-κB (NF-κB). Furthermore, the anti-apoptotic activity of MYR was demonstrated by a marked rise in Bcl-2-associated X protein (BAX)/B cell lymphoma-2 (Bcl-2) ratio by lowering Bcl-2 while increasing BAX levels. In addition, MYR treatment significantly boosted the expression of SIRT1 deacetylase in RSP-treated animals. Interestingly, molecular docking showed the ability of MYR to form a stable complex in the binding site of SIRT1. Regarding miRNAs, MYR effectively ameliorated RSP-induced changes in miR-320 and miR-107 gene expressions. Our findings afford new insights into the anti-nociceptive profile of MYR in the RSP-induced FM model in rats. The underlying mechanisms involved direct binding and activation of SIRT1 to influence different signaling cascades, including Nrf2 and NF-κB/NLRP3 together with modulation of miRNAs. However, more in-depth studies are needed before proposing MYR as a new clinically relevant drug in the management of FM. • The flavonoid MYR was isolated from Manilkara zapota leaves and quantified using HPLC. • MYR improved nociceptive and depressive-like behavior induced by RSP in rats. • MYR ameliorated RSP-induced brain oxidative stress, inflammation and apoptosis. • MYR directly bound to and activated SIRT1 to affect Nrf2 and NF-κB/NLRP3 pathways. • MYR modulated miRNA-320 and miRNA-107 gene expression in RSP-treated rats. [ABSTRACT FROM AUTHOR]

This work describes determining urea in milk samples using a multicommuted approach with a urease enzyme immobilized in bacterial cellulose and solid MOF as a colorimetric reagent. The Cu(2+)-MOF was characterized by FTIR spectroscopy, XRD, and SEM. The urea quantification was based on the urea hydrolysis reaction catalyzed by urease and reacted with Cu(2+)-MOF forming [Cu(NH 3) 4 ]2+, monitored at 450 nm. Linear responses were obtained from 1.0 to 50.0 mg dL−1 urea (R = 0.9959, n = 11), detection and quantitation limits of 0.082 mg dL−1 and 0.272 mg dL−1 respectively, analytical frequency of 8 determinations per hour, 0.8 mL sample solution consumption. Potential interfering studies have shown the selectivity of the proposed method. Addition and recovery tests were performed obtaining variation from 90 to 103%. Applying the F-test and t -test, the results showed no significant difference at the 95% confidence level Comparing the proposed and the reference method. [Display omitted] • Cu(2+)-MOF was used as an enzyme-based sensor for colorimetric detection of urea in milk. • The flow system using cellulose-immobilized urease in bacterial cellulose (BC). • Detection (LD) and quantification limits (LQ) were estimated at 0.082 mg dL−1 and 0.272 mg dL−1, respectively. • The analytical system has a significant reduction in reaction time and quantity of reagents. • The proposed analysis system is simple, versatile, and robust way and is viable to determine the urea in milk. [ABSTRACT FROM AUTHOR]

Captopril is a thiol drug, widely used for the management of hypertension and cardiovascular diseases. Reactive thiols are found to covalently modify the cysteines of plasma proteins and affect their structure and function. Human serum albumin (HSA) is prone to undergo modification by various low molecular weight compounds, including drugs. Cysteine34 (Cys34) in HSA has a free thiol group with antioxidant properties, considered to be the most redox-sensitive amino acid in plasma. Through mass-spectrometric analysis, we demonstrate for the first time that captopril forms a disulfide adduct at Cys34 residue and increases the protease susceptibility of HSA to trypsin. As evidenced by our biophysical and electron microscopy studies, HSA undergoes structural alteration, aggregation and morphological changes when treated with different captopril concentrations. Molecular dynamics studies further revealed the regions of secondary structural changes in HSA due to disulfide adduct formation by captopril at Cys34. It also elucidated the residues involved in the noncovalent interactions with captopril. It is envisaged that structural change in HSA may influence the efficacy of drug delivery as well as its own biological function. These findings may thus provide significant insights into the field of pharmacology intriguing further investigation into the effects of long-term captopril treatment. [Display omitted] • Captopril forms a disulfide adduct at cysteine 34 residue of Human serum albumin (HSA). • In bound condition, it interacts with other residues by hydrogen and Vander Waals bonds. • Captopril induces structural changes and aggregation in HSA. • Distinct morphological changes have been observed in captopril-treated HSA. [ABSTRACT FROM AUTHOR]

[Display omitted] • A rapid determination method of Ca2+ in mine wastewater based on CCDVS was proposed. • Light absorption intensity was well related to the concentration of Ca2+ (R2 = 0.997). • Light (620 nm) absorption is attributed to the complexation product of -S-O-Ca(OH)+. • The proposed method has good compatibility with calcium sources (RSD = 1.24%). • The prediction model shows low relative error (5.01%) for Ca2+ determination. Ca2+ is an important cation in coagulants used in the treatment of mine wastewater such as coal slime water, and its concentration directly affects the settling and flotation of coal slime water. The rapid determination of Ca2+ concentration is of great significance to guiding industrial production. Herein, the complexation color development—visible spectrophotometry (CCDVS) method was proposed to obtain the concentration information of Ca2+, wherein 1-(1-Hydroxy-4-methyl-2-phenylazo)-2-naphthol-4-sulfonic acid (Calmagite) was used as an indicator and the mechanism of complexation between the indicator and Ca2+ was explored. The strong correlation between spectral data and Ca2+ concentration (R2 = 0.997) indicated that this method could be used for Ca2+ detection, thereby a quantitative model was proposed to predict Ca2+ concentration by using the complexation color development—visible light absorption data. The chemical element and bonding analysis confirmed that Ca2+ was complexed with the sulfonic acid group on the indicator skeleton in the form of Ca(OH)+ intermediate in an alkaline environment. The generated complexation product (-S-O-Ca(OH)+) could stably absorb 620 nm light energy, and its absorption performance remained 99.8% after standing for 60 min. The relative standard deviation of the detection results of Ca2+ in different calcium source solutions was as low as 1.24%, which confirmed the strong calcium source compatibility of the proposed method. More importantly, the successful application of this method in the determination of Ca2+ concentration at different points in industrial coal slime water system proved its advantages of high accuracy (relative error is as low as 5.01%), low cost and simple operation. The LOD of this method is 0.038 mg/L. Therefore, the complexation color development—visible spectrophotometry method can maximize the potential for cost reduction and efficiency improvement in mine wastewater treatment. [ABSTRACT FROM AUTHOR]

• Drosophila model used to study the glial and neural specific toxicity of human APOE. • Expression level of genes regulating mitochondrial dynamics and ER stress was altered. • Lipids and metal ions concentrations in the central nervous system were disrupted. • Ethanol tolerance and cognitive function of larvae and adult flies were depleted. • These alterations mirror the main clinical manifestations of AD in patients. • HSP activation attenuates APOE4 toxic effect which demonstrated in memory performance. Alzheimer's disease (AD) is one of the most common forms of neurodegenerative diseases. Apolipoprotein E4 (ApoE4) is the main genetic risk factor in the development of late-onset AD. However, the exact mechanism underlying ApoE4-mediated neurodegeneration remains unclear. We utilized Drosophila melanogaster to examine the neurotoxic effects of various human APOE isoforms when expressed specifically in glial and neural cells. We assessed impacts on mitochondrial dynamics, ER stress, lipid metabolism, and bio-metal ion concentrations in the central nervous system (CNS) of the transgenic flies. Dachshund antibody staining revealed a reduction in the number of Kenyon cells. Behavioral investigations including ethanol tolerance and learning and memory performance demonstrated neuronal dysfunction in APOE4-expressing larvae and adult flies. Transcription level of marf and drp-1 were found to be elevated in APOE4 flies, while atf4, atf6 , and xbp- 1 s showed down regulation. Enhanced concentrations of triglyceride and cholesterol in the CNS were observed in APOE4 transgenic flies, with especially pronounced effects upon glial-specific expression of the gene. Spectrophotometry of brain homogenate revealed enhanced Fe++ and Zn++ ion levels in conjunction with diminished Cu++ levels upon APOE4 expression. To explore therapeutic strategies, we subjected the flies to heat-shock treatment, aiming to activate heat-shock proteins (HSPs) and assess their potential to mitigate the neurotoxic effects of APOE isoforms. The results showed potential therapeutic benefits for APOE4-expressing flies, hinting at an ability to attenuate memory deterioration. Overall, our findings suggest that APOE4 can alter lipid metabolism, bio metal ion homeostasis, and disrupt the harmonious fission-fusion balance of neuronal and glial mitochondria, ultimately inducing ER stress. These alterations mirror the main clinical manifestations of AD in patients. Therefore, our work underscores the suitability of Drosophila as a fertile model for probing the pathological roles of APOE and furthering our understanding of diverse isoform-specific functions. [ABSTRACT FROM AUTHOR]

The stability constants of Sm3+, Ho3+ and Y3+ complexes with EDTMP have been determined by the combination of potentiometric and spectrophotometric methods. [Display omitted] • The stability constants of Sm3+, Ho3+ and Y3+ have been determined by the combination of potentiometric and spectrophotometric methods. • These data have been compared with the data given from the literature. • The discrepancy between the data of various authors has been solved. In connection with a study of 153Sm and 90Y complexes as potential radiopharmaceutical agents, the stability constants of those formed with EDTMP (ethylenediamine-N,N,Ń,Ń-tetra(methylenephosphonate)) were calculated using data from potentiometric and spectrophometric titrations measured at 25 °C in 0.1 mol/l NaCl. The following values were obtained for the stability constants of the Sm3+ − EDTMP complexes SmH -1 L6-, SmL5-, HSmL4-, H 2 SmL3-, H 3 SmL2- and H 4 SmL-: log β = 7.56, 19.08, 27.75, 34.76, 40.16 and 45.55 respectively. The corresponding stability constants of the Y3+ − EDTMP complexes YH -1 L6-, YL5-, HYL4-, H 2 YL3-, H 3 YL2- and H 4 YL- were log β = 10.47, 19.96, 28.13, 35.06, 40.35 and 46.13. A diagram of the complexes speciation dependence on pH shows that the complex forms HML4-and H 2 ML3- (M = Y or Sm) are characteristic of the pH range 6–8, which is suitable for application into the human body. [ABSTRACT FROM AUTHOR]

[Display omitted] • Novel smartphone-based methods for wine analysis were developed. • Developed methods were applied for the determination of bioactive compounds in wines. • Smartphone-based detection facilitates in-field analysis. • Proposed solution can be used in routine food quality assessment. • The obtained results were comparable to those obtained with UV/Vis spectrophotometry. A set of simple smartphone-based methods of bioactive compounds determination were developed for wine analysis. Procedures for smartphone-based determination of the total content of phenolic compounds, flavonoids, anthocyanins and biogenic amines, as well as measurement of antioxidant activity were developed and fully validated. The experimental setup is based on smartphone and 3D-printed device, though it is very simple and can be conveniently applied in lab and in field. The proposed solutions have satisfactory figures of merit with R2 in the range of 0.9860–0.9981 for linear range. The recoveries were in range 98.6–102%, RSDs up to 4.2% and LODs below 2.3 mg/L. In order to demonstrate the applicability of the proposed procedures, wine samples were analysed using spectrophotometry and newly developed methods. The results of application of smartphone and spectrophotometer are comparable, in terms of validation parameters and measured concentrations in real samples. [ABSTRACT FROM AUTHOR]

Gastrodia elata Blume is a traditional Chinese medicine with the effects of improving the deficiency of the body and maintaining health, and polysaccharide (GEP) is one of the effective ingredients to play these activities of G. elata. Traditionally, G. elata is orally administered, so the activities of GEP are associated with digestive and intestinal metabolism. However, the digestive behavior of GEP and its effects on the human gut microbiota are unclear and need to be fully studied. This study aimed to investigate the changes in structural characteristics of GEP during digestion and the related impacts of its digestive product on gut microbiota in human fecal fermentation, and to explain the beneficial mechanism of GEP on human health from the perspective of digestive characteristics and "gut" axis. The changes of reducing sugars, free monosaccharides and physicochemical properties of GEP during digestion were investigated by GPC, HPLC, FT-IR, CD, NMR, SEM, and TGA. Moreover, polysaccharide consumption, pH value changes, SCFAs production, and changes in gut microbiota during fermentation were also discussed. During digestion of GEP, glucose was partially released causing a decrease in molecular weight, and a change in monosaccharide composition. In addition, the characteristics of GEP before and after digestion, including configuration, morphology, and stability, were different. The digestive product of GEP was polysaccharide (GEP-I), which actively participated in the fecal fermentation process. As the fermentation time increased, the utilization of GEP-I by the microbiota gradually increased. The abundance of probiotics such as Bifidobacterium , Collinsella , Prevotella , and Faecalibacterium was significantly increased, and the abundance of pathogenic Shigella , Dorea , Desulfovibrio , and Blautia was significantly inhibited, thereby suggesting that GEP has the potential to maintain human health through the "gut" axis. In addition, the beneficial health effects of GEP-I have also been observed in the influence of microbial metabolites. During the fermentation of GEP-I, the pH value gradually decreased, and the contents of beneficial metabolites such as acetic acid, propionic acid, and caproic acid significantly increased. The structure of GEP changed significantly during digestion, and its digestive product had the potential to maintain human health by regulating gut microbiota, which may be one of the active mechanisms of GEP. [Display omitted] • The physicochemical properties of GEP were significantly changed after digestion. • The digestive product (GEP-I) of GEP actively participates in fecal fermentation. • GEP had the potential to maintain human health through the "gut" axis. [ABSTRACT FROM AUTHOR]

[Display omitted] • Di(2-ethylhexyl)phosphoric acid salt was used as a surfactant for SUPRAS formation. • Inorganic electrolytes were shown to serve as coacervation agents in this system. • Sodium carbonate and sodium phosphate created alkaline medium to form amphiphiles. • Density, viscosity and pH values of the novel SUPRASs were obtained. • Liquid-phase microextraction approach for determination of antipyrine in saliva. In this study, di(2-ethylhexyl)phosphoric acid salt was investigated as a double-chain anionic surfactant for supramolecular solvent formation in a liquid-phase microextraction procedure for the first time. Inorganic electrolytes (sodium salts) were shown to be coacervation agents, due to their salting-out property in solution of sodium di(2-ethylhexyl)phosphate, obtained by deprotonation of the acid. The physico-chemical properties of the newly synthesised solvents were studied. Sodium carbonate and sodium phosphate were found to be the most suitable coacervation agents, due to their alkaline nature and low viscosity of the supramolecular solvent phases they produce. The extraction ability of the novel solvent was demonstrated in liquid-phase microextraction of a colored derivative of antipyrine from saliva for further spectrophotometric determination. The extraction recovery was found to be 70 %. The proposed green sample preparation technique enabled the exclusion of traditional toxic solvents and reduction of reagent consumption. The satisfactory analytical performance of the procedure was validated with real sample analysis. The calibration graph was linear over the concentration range of 0.03 to 0.5 mmol/L. The limit of detection (3σ) and limit of quantification (10σ), calculated from blank tests, were 0.01 and 0.03 mmol/L, respectively. [ABSTRACT FROM AUTHOR]

[Display omitted] • First report on % level quantification of Nb in Gd 2 Zr 2 O 7 , a burnable poison. • Simple and quick dissolution of Gd 2 Zr 2 O 7 using ammonium bifluoride fusion. • Selective and quantitative recovery of Nb was achieved from refractive Gd 2 Zr 2 O 7. • Formation of aqueous soluble (NH 4) 3 NbOF 6 & NH 4 NbOF 4 confirmed by XRD. • Developed method successfully extended to real sample analysis. A simple and reliable method for the determination of percentage level niobium (3.5-8 %) in highly refractive gadolinium zirconate (Gd 2 Zr 2 O 7) doped with niobium, a burnable poison material of nuclear reactor has been proposed. A fusion procedure using ammonium bifluoride (ABF) with Gd 2 Zr 2 O 7 was developed. Fusion conditions such as time, temperature and ABF to sample ratio were optimised for realizing quantitative recovery of Nb. The fused masses obtained under different conditions were characterized using SEM-EDX and XRD to comprehend the conversion of the refractive oxide form to soluble fluoro compounds and their identification. The real samples fused under optimized conditions were dissolved in 2 % tartaric acid solution and the same was used for quantifying Nb employing spectrophotometry using 5-bromo pyrogallol red as chromogenic agent. Precision of the measurements was better than 3 % (RSD) for Nb(V) at 0.5 ppm and the accuracy of the method is 99.8 %. [ABSTRACT FROM AUTHOR]

Analyzing nutrient samples (including nitrate, nitrite, ammonium, phosphate, and silicate) immediately after sampling is highly recommended in the aquatic environment to reduce the possibility of biological growth and decay during sample storage. Numerous papers have been published reporting new methods for the determination of nutrients. However, among the portfolio of available analytical methods, only a handful of approaches offer clear application (or potential) for field analysis, in terms of adequate analytical features, autonomy, feasibility of miniaturization, robustness, and ease of portability. Spectrophotometry, the classic and most commonly used methodology for nutrients determination, is a well-established wet chemistry method based on the formation and detection of a strongly absorbing dye, which has been adopted as the standard method. This article provides a comprehensive overview of the most pertinent publications regarding the on-site determination of nutrients in aqueous samples using spectrophotometric methodologies from 2019 to 2023. Additionally, recommendations regarding future research and development are also discussed for further advances and improvements. [Display omitted] • Overview of the spectrophotometric methods for on-site nutrient determination in water samples. • Summary of the state-of-the-art techniques coupled with spectrophotometric methods (2019–2023). • Discussion of challenges encountered by on-site methods and instruments for field application. • A prospective view on the future development of on-site nutrient measurement. [ABSTRACT FROM AUTHOR]

In vitro precipitation assays are often applied to support drug and formulation development. Current methods applied to quantify the amount of dissolved drug, in particular (U)HPLC, require time-consuming sample preparation. Furthermore, small precipitates formed during the nucleation phase may not be removed quantitatively by filtration or centrifugation of the sample. Given the drawbacks of standard (U)HPLC analyses during the application in transfer experiments, it was the aim of this work to develop a robust and simple to implement in-line UV spectrophotometric method which accurately reflects the precipitation profile obtained from in vitro transfer assays. Based on the three model compounds cinnarizine, dipyridamole, and ketoconazole, the manuscript describes the development of a design of experiments (DoE) based approach to develop derivative UV spectrophotometric methods accounting for the change in media composition over time due to the dilution of simulated intestinal with simulated gastric fluid. An R script was developed which automatically identifies suitable wavelengths for in-line measurements. As an outcome of this study, a fast, robust, accurate, and specific derivative UV spectrophotometric methodology for measuring the concentration of dissolved drugs in in vitro transfer experiments was successfully developed. This method can flexibly be applied to multi-compartmental precipitation assays. [ABSTRACT FROM AUTHOR]

Real time analysis of pharmaceuticals in controlled release nano and microsystems remains a challenge. It is hypothesized that fluorine 19 nuclear magnetic resonance (19F qNMR) can be used for real time quantification and in vitro release of maraviroc (MVC). The release of maraviroc was analyzed in simulated body fluids from spray dried sodium alginate microspheres (MS) using the 19F qNMR method. Calibration produced a linearity curve in concentration range (0.42 mg/ml – 15 mg/ml), and the limits of detection and quantification values were 0.97 mg/ml and 2.93 mg/ml, respectively. The method was confirmed to be specific, accurate, precise, and robust (%RSE > 2%). MVC was successfully microencapsulated (18% w/w) as evidenced by the FT-IR spectra and SEM images. The MS had an average diameter of 2.522 ± 0.15 μm, with a zeta potential of – 61.31 ± 2.1 mV. Overall, the 19F qNMR method enabled a direct and real time quantification of MVC for an efficient drug release kinetics. This approach could be potentially used to quantify fluorinated drug potency, purity, and stability, and evaluate in vitro release kinetic from different formulations. [ABSTRACT FROM AUTHOR]

The aim of this study was to evaluate the bleaching effect after aging simulation in teeth submitted to bonding and debonding of orthodontic brackets. For this study, 90 human premolars were selected, and randomly divided into 6 groups: control, bleaching, and other 4 groups submitted to bleaching after bonding and debonding brackets using different methods. Color measurement of sample through the CIE L*a*b* system was performed in three moments: T1 – after brackets debonding, T2 – after staining cycling, and T3 – after bleaching. For evaluation of results among the components L*, a* and b*, the two criteria analysis of variance and the multiple comparison Tukey test (p < 0.05) were used. Statistically significant difference was observed among the groups submitted to brackets bonding and debonding through self-conditioning adhesive system and tungsten drill, also the control and bleaching groups between the moments T1 e T2. Bonding and debonding brackets methods tested in this study showed influence on the sample color change, and after the tooth bleaching process, only the group without brackets previous bonding achieved the color value presented before the staining and aging of samples in the brackets absence. [ABSTRACT FROM AUTHOR]

[Display omitted] • 54 different populations of Corydalis DC. were screened for anticholinesterase activities. • Strong anticholinesterase activity was shown by Corydalis DC. genus. • 7 bioactive isoquinoline alkaloids were identified by spectroscopic techniques. • The protoberberine alkaloids got strong anticholinesterase activity. • This research is the first study in terms of the identification of bioactive compounds of Corydalis. The aim of the present study is to determine the in vitro cholinesterase inhibitory effects of the tubers of Corydalis DC. species growing in Turkey belonging to Papaveraceae family. This genus comprises of approximately 470 species distributed in the world and is represented 17 species and 22 taxons, 8 of which are endemic, in the flora of Turkey. Some Corydalis species are used in folk medicine for the memory enhancement in Europe and China. Acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibitory activities of the ethanolic extracts prepared from tubers collected from 54 populations are screened by the slightly modified spectrophotometric method. The highest anticholinesterase compound/s were determined by assay-guided fractionation and their structures were elucidated through chromatographic (LC-Q-ToF-MS) and extensive spectroscopic techniques. According to the results, canadine, berberine and dehydrocorydaline from protoberberine-type isoquinoline alkaloids were exerted the most potent inhibitory effect against two enzymes. This is the first study determining anticholinesterase compounds of Corydalis species growing in Turkey. [ABSTRACT FROM AUTHOR]

Amyloids share a common architecture but play disparate biological roles in processes ranging from bacterial defense mechanisms to protein misfolding diseases. Their structures are highly polymorphic, which makes them difficult to study by X-ray diffraction or NMR spectroscopy. Our understanding of amyloid structures is due in large part to recent advances in the field of cryo-EM, which allows for determining the polymorphs separately. In this review, we highlight the main stepping stones leading to the substantial number of high-resolution amyloid fibril structures known today as well as recent developments regarding automation and software in cryo-EM. We discuss that sample preparation should move closer to physiological conditions to understand how amyloid aggregation and disease are linked. We further highlight new approaches to address heterogeneity and polymorphism of amyloid fibrils in EM image processing and give an outlook to the upcoming challenges in researching the structural biology of amyloids. [ABSTRACT FROM AUTHOR]

• In this study, a novel UV–Vis spectrophotometry-colorimetric method was developed and validated. • This method was used to measure the concentration of rivastigmine tartrate (RT) in various biological matrices after the application of separable-effervescent microneedles (SEMNs) containing RT. • This method was successfully applied in ex vivo and in vitro permeation , along with in vivo pharmacokinetic studies. Rivastigmine Tartrate is an acetylcholinesterase inhibitor commonly used in Alzheimer treatment. Due to its hydrophilicity, short plasma elimination half-time, and poor blood-brain barrier penetration, developing a new drug delivery system for RT administration is essential. Accordingly, microneedles offer several advantages and could be a promising drug delivery system for RT administration. One of those types of MNs with numerous advantages is separable-effervescent microneedles. To support the formulation development, an analytical method using UV–Vis spectrophotometry was validated in phosphate buffered saline media and various biological matrices, such as rat skin, brain, and plasma to measure the amount of RT in the SEMNs preparations. The developed analytical method was validated under ICH guidelines. The results showed that the instrument could specifically detect the RT in the preparations without being interfered with by other compounds. The calibration curves in various biological matrices were linear ≥ 0.9985. The LOD and LLOQ values of the PBS media biological matrices were found to be 1.5 and 4.8 µg/mL, 1.2 and 3.7 µg/mL, 0.42 and 1.27 µg/mL, and 0.38 and 1.16 µg/mL, respectively. All the accuracy and precision values of this developed method were within acceptable ranges. Additionally, the extraction recovery was prominent after undergoing the protein precipitation process. As a result, the analytical method was proven to be valid and was successfully applied to quantify the amount of RT in the SEMNs formulation, in vitro and ex vivo permeation, along with in vivo pharmacokinetic studies. [Display omitted] [ABSTRACT FROM AUTHOR]

We present a newly developed method which combines the nonlinear spectral mixing model of Shkuratov et al. (1999) with a machine learning algorithm to map the lunar regolith composition using spectral data. The new method performs orders of magnitude faster than the traditionally used numerical optimization approaches, allowing the mapping of regolith properties (including mineralogical composition, average grain size and optical maturity) over large areas of the lunar surface. A new set of basic mineral spectra of the lunar soil for using with spectral mixing models is proposed. Used together with the nonlinear mixing model (Shkuratov et al., 1999), the set is able to describes Chandrayaan-1 M3 instrument spectra collected from test areas which includes the Shapley crater with its surroundings containing mare and highland terrains well. The new set includes a virtual "gray component" with a "flat" (constant) spectrum, accounting for the factors that change general surface albedo, such as spectrally neutral components (e.g., agglutinate glasses), errors in the photometric reduction, uncertainties in estimations of lunar regolith porosity q and the mean grain size S of the basic minerals. The proposed new method takes into account the influence of space weathering and nonlinear correlation between the compositional and spectral parameters of the lunar soils delivering values for the optical properties and mineralogical abundance determination of the lunar regolith which are compatible with the results found from lunar samples measurements in the laboratory. The proposed approach can be used for analyzing spectral observations not only of the lunar surface but also for other surfaces with are covered by regolith. • A new method of mineralogy mapping combining the Shkuratov spectral mixing model with machine learning is proposed. • The method is computationally efficient and removes ambiguities in the spectral unmixing results. • The method allows a mapping of the mineralogical composition, grain size and maturity over large lunar surface areas. • The method was tested on a lunar area near the crater Shapley using the Chandrayaan-1 M3 hyperspectral imager data. • The method provides regolith parameters values which are in agreement with the values found through lunar sample analysis. [ABSTRACT FROM AUTHOR]

• The Ge(IV) interaction with novel ligand have been studied by spectrophotometry and DFT calculation. • A room-temperature cloud point extraction (RT-CPE) procedure has been proposed. • RT-CPE coupled to spectrophotometry and successfully applied to Ge(IV) traces analysis. In the current study, a novel and fast procedure for room-temperature cloud point extraction of Germanium (VI) followed by spectrophotometric detection is developed. A 6,7-dihydroxy-2,4-diphenyl-1-benzopyran-1-ium bromide (DPBP) reagent was proposed for binding Ge (IV) into the extractable colored complex. The interaction of Ge (IV) with the reagent DPBP was studied using spectrophotometry and density functional theory (DFT) calculations. It was established that the complex stoichiometry is 1:2. It was shown that with the increase of the charge of the resulting complex, the Gibbs free energy of the complex formation increases considerably. This means that the formation of neutral species with cis- location of the hydroxyl ligands is the most preferable process. The cloud point phenomenon at room temperature was immediately initiated via ammonium benzoate. The calibration plot for Ge (IV) was obtained in the concentration range of 4–490 μg L−1 under optimized conditions: pH = 1, concentration of DPBP 1.8–2∙10-5 mol/L, 0.12 mol/L aqueous ammonium benzoate and 1 % (v/v) Triton X-100). The limit of detection is 1.2 μg L−1. The method was successfully applied to the determination of Ge(IV) traces in vegetable and rock samples. [ABSTRACT FROM AUTHOR]

This paper presents the results of studying the acid-base properties of the indicator dye methyl yellow in water–ethanol solutions with a volume fraction of alcohol of 10 % and 50 %. The influence of the addition of NaCl salts and tetrabutylammonium chloride, as well as the anionic surfactant sodium dodecylsulfate (SDS) on the acidity constant of the indicator, was evaluated. Under the chosen conditions, ethanol additives have a more significant effect on the p K a value. For the first time, using the dynamic light scattering method, the particle sizes, polydispersity index, and ζ-potential of colloidal particles in pure aqueous and mixed water–ethanol solutions of methyl yellow (φ alcohol from 0.2 % to 50 %) in the presence of NaCl and SDS were estimated. In solutions with φ alcohol = 50 % colloidal particles were not found. It has been shown that the hardened gelatin gel of photographic film can be used as a convenient sorbent for methyl yellow. In the process of dye extraction into a gelatin film from water-alcohol solutions containing SDS and NaCl, the acid-base properties of the methyl yellow remained almost unchanged. The difference between the p K a values obtained for the indicator both in solution and in the film did not exceed the measurement error. [ABSTRACT FROM AUTHOR]

In this study, we developed a spectrophotometry method for the analysis of 5-hydroxymethylfurfuraldehyde (HMF) in pharmaceutical formulations using citrate@Fe 3 O 4 adsorbent. As bare magnetite (Fe 3 O 4) has certain limitations, such as aggregation and oxidation, surface modifications are commonly used to improve its properties. We successfully coated Fe 3 O 4 with sodium citrate to create a magnetic adsorbent for isolating HMF from samples. We confirmed the successful surface coating of Fe 3 O 4 with citrate using Fourier Transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), Zeta potential, and scanning electron microscopy (SEM). The high adsorption capacity of citrate@Fe 3 O 4 is due to the abundance of carboxyl and hydroxyl groups on the surface of the adsorbent, making it ideal for HMF extraction. The HMF concentration was then quantified using spectrophotometry. Citrate@Fe 3 O 4 exhibited a high surface area and strong interaction with HMF. We analyzed the individual influential factors affecting the magnetic solid phase extraction (MSPE) setup. Validation parameters were also provided to confirm the reliability of the method. Under optimal parameters, the method exhibited excellent linearity in the range of 0.05–30.00 μg/ml with the lower limit of quantification (LLOQ) of 0.05 μg/ml. Relative standard deviations (RSD) values for precision were better than 10% and the method's trueness were better than 10%. Recoveries were found to be in the range of 85% to 106%, indicating excellent accuracy and reliability. We used this method to identify and measure HMF in six different dextrose pharmaceutical dosage forms as intravenous injectable solutions and three honey samples. • Synthesis and characterization of a citrate@Fe 3 O 4 nanoadsorbent for selective HMF extraction. • Optimization of a magnetic solid phase extraction method for HMF. • Accurate HMF quantification in pharmaceutical formulations via spectrophotometric analysis. [ABSTRACT FROM AUTHOR]

[Display omitted] • Green spectrophotometric methods for antiretroviral drugs. • High-accuracy Abacavir and Lamivudine analysis. • Methods comply with standard ICH guidelines. • Minimal use of hazardous substances in analysis. • High green metrics denote environmental sustainability. Herein, two different sustainable and green signal processing spectrophotometric approaches, namely, derivative spectroscopy and wavelet transform, have been utilized for effective measurement of the antiretroviral therapy abacavir and lamivudine in their pharmaceutical formulations. These methods were used to enhance the spectral data and differentiate between the absorption bands of abacavir and lamivudine in order to accurately measure their concentrations. For determining abacavir and lamivudine, the first derivative spectrophotometric method has been applied to the zero-order and ratio spectra of both drugs. The same approach has been tested using the continuous wavelet transform method where a second order 2.4 of rbio and bior wavelet families were found to be optimum for measuring both drugs. Validation of the proposed methods affirmed their reliability in terms of linearity over the concentration range 1.5–30 µg/mL and 1.5–36 µg/mL for abacavir and lamivudine, respectively, precision (RSD < 2 %), and accuracy with mean recoveries ranging between 98 % and 102 %. Additionally, these spectrophotometric methodologies were applied to real pharmaceutical preparations and yielded results congruent with a prior chromatographic method. Most prominently, the proposed methods stood out for their greenness and sustainability with 97 points as evaluated by the analytical eco-scale method and a score value of 0.79 as analyzed by AGREE method, thereby making them suitable for resource-limited settings and highlighting the potential for broader application of green analytical methods in pharmaceutical analysis. [ABSTRACT FROM AUTHOR]

[Display omitted] • Sacubitril (SAC) and valsartan (VAL) are angiotensin receptor-neprilysin inhibitors used to reduce morbidity and mortality in patients with chronic, symptomatic heart failure. • Active substances are quantified as simple, quick, without the need for pre-separation due to developed methods. • The HPLC method has a short analysis time, the amount of waste is low and it is sensitive to the environment. • HPLC-UV and spectrophotometric methods are used and applied to the pharmaceutical preparation. A novel high performance liquid chromatography (HPLC) and spectrophotometric analysis were applied for quantification of active substances of sacubitril (SAC) and valsartan (VAL). HPLC experiments were conducted on the Waters Spherisorb® (3.0 µm 60.0x4.0 mm) column. Preparation of mobile phase A: 200 mL of 0.1 % solution of trifluoroacetic acid in water and 800 mL of 0.1 % solution of trifluoroacetic acid in acetonitrile by volume are mixed. Preparation of mobile phase B: 800 mL of a 0.1 % solution of trifluoroacetic acid in water and 200 mL of 0.1 % solution of trifluoroacetic acid in acetonitrile by volume were mixed. It was given to the system at the ratio of Mobile Phase A: Mobile Phase B (35:65 v:v). The specimen was injected into the column at 15.0 µL. A detection wavelength of 254.0 nm was preferred for the compound and the flow rate was 2.0 mL/min. Analysis was completed in 4.0 min. The column oven temperature was adjusted to 40.0 °C. The methods were evaluated in terms of green chemistry. The methods have been validated according to ICH guidelines. For HPLC method calibration graphs were constructed in the 20.0– 145.0 and 20.0 – 155 µg/mL SAC and VAL respectively with an R2 of 1.000. In recovery experiments, the RSD values were calculated to be 0.08 % and 0.34 % for SAC and VAL, respectively. Additionally, in intraday and interday experiments, percent RSD values were found to be between 0.23 and 0.49. The method developed for the analysis of the active substances has been developed with a short analysis time and is cost effective. SAC and VAL were determined using a novel method for spectrophotometric analysis. The determination was performed simultaneously using the applied method. This method is a constant center method. Calibration graphs were constructed in the 2.0– 20.0 and 2.0 – 25 µg/mL SAC and VAL with an R2 of 0.9998 and 0.9999 respectively. It is a greenness method in terms of the analysis time and solvent used. [ABSTRACT FROM AUTHOR]

[Display omitted] • The development of LCW and its applications in spectroscopy are briefly introduced. • The working principle, types, and characteristics of Teflon AF LCW are summarized. • The different detection methods and application fields of Teflon AF LCW are reviewed. • The current challenges and future opportunities for Teflon AF LCW are emphasized. Liquid core waveguide (LCW) is well known as a sampling, light path and signal enhancement tool for miniaturized or portable instrumentation of spectroscopic analysis such as absorption, fluorescence, and Raman spectroscopy. Total internal reflection (TIR) occurs in various LCW apparatus to increase the optical path and thereby enhance detection sensitivity by several orders of magnitude. Teflon AF is made up of tetrafluoroethylene and 2,2-difluoromethyl-4,5-difluoro-1,3-dioxide. In this review, the working principle, different types, and characteristics of Teflon AF LCW were systematically discussed. The different detection methods based on Teflon AF LCW, including absorbance spectrophotometry, fluorescence spectrophotometry, and Raman spectroscopy, were then discussed in detail. The application fields for Teflon AF LCW were also summarized, involving metallic ions, N, S, pesticide and veterinary residues, protein-based medicines, and other compounds in food, environmental, biological, medicine samples. The current challenges and potential future opportunities for Teflon AF LCW were emphasized to improve their study and application. [ABSTRACT FROM AUTHOR]

In this work, a simple, time saving, accurate and sensitive method for the direct spectrophotometric detection of cobalt ion using two new fluorophore azo dyes, R1 and R2, were achieved. The method based on a complex formation between Co(II) and these two azo compounds-based fluorene and pyrene moieties. To attain the optimal conditions for the detection of cobalt ion, several parameters such as effect of solvents, pH, reagent concentration, sequence of addition, temperature and time were explored. The absorption maximum for Co(II)-R1 and Co(II)-R1 orange color complexes was accomplished at 472 nm using pH 8.97 of universal buffer and 470 nm using pH 10.98, respectively. The calibration graphs were linear over the concentration range of 0.2–3 and 0.4–3 µg mL−1 of Co(II) for Co(II)-R1 and Co(II)-R1, respectively with a stoichiometric ratio of (1:2) (Co2+: reagent). Various statistical analytical parameters including molar absorptivity, limit of detection, limit of quantification, precision and accuracy were estimated. In addition, the established approach was efficiently exploited for Co(II) determination in some water samples. The findings of this investigation may pave the way for advancements in sensor technologies. [ABSTRACT FROM AUTHOR]