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Ascorbic acid (AA) or vitamin C, is vital in food safety, pharmaceutical and biomedical industries. This review discusses recent advancements in biosensors for AA detection. Traditional macro-analysis techniques such as high-performance liquids chromatography (HPLC), and flow injection analysis (FIA) provide accurate measurements but are costly and require specialized handling. Miniaturized nano-sensors are emerging as promising alternatives, offering advantages such as portability, cost effectiveness, and rapid response. This review explores the working principles of these nano-sensors, highlighting colorimetric, fluorometric and electrochemical detection methods. It also outlines the current AA biosensing landscape, detailing strategies to improve selectivity and specificity, including the choice of biorecognition elements and material selection for detection probe synthesis. Emerging nanomaterials and their applicability to support sensing activity are explored. This review serves as a valuable resource, suggesting future research directions to address existing challenges and further advance biosensor technology. [ABSTRACT FROM AUTHOR]

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AbstractA flow injection (FI) method employing the reaction between 1,10-phenanthroline (C12H8N2) and hydrogen peroxide (H2O2) in a basic medium (pH 12) with chemiluminescence (CL) detection has been developed to detect copper oxychloride pesticides in freshwater and fruit samples. The experimental conditions were optimized, and a solid phase extraction (SPE) technique modified with cupron was employed for effective phase separation during extraction. Calibration curves for copper oxychloride standard solutions demonstrated linearity over the range of 0.001 to 10 μg L−1, with the regression equation y = 506681x − 422.29 and a coefficient of determination (R2) of 0.9973 (n = 9). The limits of detection (LOD) and quantification (LOQ) were determined to be 2.62 × 10−4 μg L−1 and 7.94 × 10−4 μg L−1, respectively. Relative standard deviations (RSDs) ranged from 2.6% to 4.5%, and the method achieved an injection throughput of 120 h−1. When applied to spiked water and fruit samples, the method showed no significant differences at the 95% confidence level compared to established methods. Recoveries for copper oxychloride were found to range from 96% to 120% (RSD = 1.9 − 5.6%) in fruit samples and from 95% to 110% (RSD = 1.5 − 4.8%) in water samples. Additionally, the potential chemiluminescence reaction mechanism was investigated. [ABSTRACT FROM AUTHOR]

The quality and the security of preparations in hospital centres are essential to guarantee the patient's safety. The development of fast and efficient analytical methods is required to control the finished product before use. In this context, the study aimed to compare the performance and interchangeability of two spectral analytical methods: the flow injection analysis (FIA) with UV detection and the Raman spectroscopy for the quality control of preparation before use to quantify the remdesivir as a SARS‐CoV‐2 drug. A quantitative study of remdesivir was performed using clinically relevant concentration solutions ranging from 0.25 to 1.625 mg.mL−1 in 0.9% NaCl. Samples were analysed by FIA‐UV at 245 nm and by a handheld Raman spectroscopy at 785 nm. Quantitative models were developed using a calibration set (n = 45 samples) and optimized using a validation set (n = 27). An external validation test set (n = 58) was used to compare the two methods by a Bland–Altman plot. Partial least square regression was used to analyse Raman spectra, while univariate analysis was performed at 245 nm for FIA‐UV. The regression coefficient was higher than 0.990 for both methods, and the root mean square error of prediction was 0.031 mg.mL−1 for Raman spectroscopy. The Bland–Altman plot confirmed the interchangeability of the two methods and the potential of Raman spectroscopy to control remdesivir during clinical preparation in the hospital. [ABSTRACT FROM AUTHOR]

Analytical instrumentation is essential for chemical analysis in many fields, including biology and chemistry, but it can be costly and inaccessible to many educational institutions because it often requires expensive and sophisticated equipment. To address this issue, there has been growing interest in developing new and accessible alternatives. In this study, we developed a low-cost and user-friendly spectrophotometric detector based on an Arduino UNO platform. This detector was coupled with a flow injection analysis system (FIA) and used to quantify the concentration of tartrazine in commercial beverages and candy samples. The proposed miniaturized detector offers an affordable and portable alternative to conventional spectrophotometers. We evaluated the performance of our detector by comparing its results with those obtained using high-performance liquid chromatography (HPLC-DAD), and the accuracy and precision were comparable. The results demonstrate the potential of the Arduino-based spectrophotometric detector as a cost-effective and accessible tool, with potential applications in food science, environmental monitoring, and other fields. [ABSTRACT FROM AUTHOR]

The electrochemical detection of two pharmaceuticals, diclofenac (DCF) and carbamazepine (CBZ), was investigated as an oxidation current using boron‐doped nanocrystalline diamond (BDD) thin‐film electrodes. Both voltammetry and flow injection analysis with amperometric detection (FIA‐EC) were used to measure the drugs in standard solutions and a urine simulant. The oxidation potential for DCF was ca. 0.7 V vs. Ag/AgCl (3 M KCl) in 0.1 M phosphate buffer (pH 7.2) and was ca. 1.2 V for CBZ in 0.1 M perchloric acid. The DCF oxidation reaction was diffusion controlled at the detection potential with evidence of some surface fouling by reaction products. The CBZ oxidation reaction was also controlled by diffusion at the detection potential, but with no surface fouling. The voltammetric peak currents for both drugs increased linearly with the concentration in the micromolar range (r2≥0.994). FIA‐EC analysis of DCF and CBZ revealed a linear dynamic range from at least 0.1 to 100 μM with the actual minimum concentration detectable (S/N=3) being less than the lowest concentration measured. The recovery percentage for DCF in the urine simulant ranged from 94–108% and from 97–100% for CBZ, both assessed using square wave voltammetry. FIA‐EC data revealed that the BDD electrodes offer excellent intra and inter‐electrode repeatability with an RSD for DCF and CBZ of 4.90% and 3.81%, respectively. The BDD electrode provided good reproducibility and response stability over eight days of continuous use detecting both DCF and CBZ. Overall, BDD electrodes are a viable material  for the sensitive, selective, and reproducible electrochemical detection of these two pharmaceuticals. [ABSTRACT FROM AUTHOR]

Recently, attention has turned to drugs like salicylamide for treating COVID-19. Several studies have reported simple, fast, and sensitive methods for measuring salicylamide levels. However, potential limitations remain regarding interference from other drugs and accuracy of results. To tackle this issue, researchers combined the standard addition technique with flow injection analysis. As part of this investigation, the reaction involving Fe (III), salicylamide, and 1,10-phenanthroline at a temperature of 55°C was examined using a spectrophotometer set at a wavelength of 528 nm. Thus, the new design was able to show an excellent linearity over the concentration range of (2-30 μg/mL) and (25-300 μg/mL), with correlation coefficients (r² ) of 0.9669 and 0.9781, respectively. In addition, physical and chemical variables were optimized to obtain the best results. There was a significant positive correlation between the new design and SCÏO NIR micro-spectrometers device (handheld) outcomes. [ABSTRACT FROM AUTHOR]

This review focuses on monosodium glutamate which proclaims the fifth taste as "Umami". Monosodium glutamate imparts a deep, meaty, umami flavour to foods. Asian cuisine frequently uses this flavouring, just as in the processed items produced across the United States and Europe. This article dealt with a detailed discussion of physicochemical features, pharmacological actions, and different reported analytical methodologies for the estimation of monosodium glutamate. Monosodium glutamate is analyzed using a variety of techniques, including spectroscopy, chromatography, electrochemistry, electrophoresis, chemometrics, flow injection analysis, and biosensors. According to results of comparative research of analytical methodologies, high performance liquid chromatography (HPLC) is most widely used method for analyzing monosodium glutamate which surpasses the gas chromatographic (GC) approach. All of the reported methods are accurate, precise, cost-effective, and sensitive. The European Union defined monosodium glutamate as a food additive that is permitted in some foods, but is subject to quantitative limits. Consequently, this study provides the analyst with an accessible path to quantifying monosodium glutamate's content for use in the food and pharmaceutical industries. [ABSTRACT FROM AUTHOR]

Abstract A novel antipsychotic medication named brexpiprazole (BRX) is currently employed for the treatment of schizophrenia and other psychotic disorders. Because BRX’s molecular structure includes a benzothiophene ring, it natively fluoresces. To detect BRX with precision and speed, a flow injection-fluorometric method, which is both sensitive and selective, is recommended. The fluorescence detection was conducted at 364 nm following excitation at 326 nm to capture the strong intrinsic fluorescence of BRX. The carrier solution employed was a mixture of phosphate buffer (pH 4, 10 mM) and acetonitrile (50: 50, v/v), with a flow rate of 0.5 mL min− 1. The calibration curve, based on peak areas, exhibited linearity within the concentration range of 20–350 ng mL− 1, with a remarkable correlation coefficient (r2) of 0.9999. The limit of quantitation was 9.7 ng mL− 1, and the limit of detection was found to be 3.2 ng mL− 1. This method was applied to quantify BRX in Neopression® tablets, achieving recovery within an acceptable range without interference from the tablet’s additives. Additionally, the proposed approach was successfully utilised to quantify the drug in spiked human plasma. The approach underwent validation following ICH requirements.

The detection and quantification of pharmaceutical compounds in various matrices, including environmental and biological samples, has received a great deal of attention due to their potential impact on human health and the environment. In this study, we present an electrochemical approach for the determination of nimesulide, a commonly used non-steroidal anti-inflammatory drug, in water supply, synthetic urine and drug samples. A 3D-printed electrochemical sensor was fabricated and modified by an electrochemical treatment in alkaline medium with KOH, followed by the electrodeposition of silver nanoparticles to improve its detection capabilities. The performance of the electrochemical sensor was evaluated by multiple techniques and a flow injection analysis with amperometric detection was applied for the quantification of nimesulide. The FIA-AMP system allowed for the efficient introduction of samples, promoting rapid analysis and minimizing memory effects. The sensor connected to the method showed good sensitivity (0.171 ± 0.002 µA L mol−1 cm−2) and improved stability (RSD < 7%) and its electrochemical responses were correlated with the concentration of nimesulide present in the samples tested, with recovery values in the 92 to 104% range. The method developed showed a good linear range from 5 to 25 µmol L−1 and a low detection limit of 0.81 µmol L−1, which makes it suitable for the quantitative analysis of nimesulide over a range of concentrations. The sensor applied to the determination of nimesulide offers a promising platform for the sensitive and selective detection of pharmaceutical compounds, contributing to greater safety and sustainability in these fields. [ABSTRACT FROM AUTHOR]

SARS-CoV-2 infection was shown to induce proprotein convertase subtilisin/kexin type 9 (PCSK9) plasma levels in sepsis. Here, we investigate the association between serum PCSK9 levels and disease severity. PCSK9 was measured in serum of 55 controls, 40 patients with moderate and 60 patients with severe COVID-19 disease. Serum PCSK9 was elevated in moderate COVID-19 compared to controls and further increased in severe cases. PCSK9 levels were not associated with C-reactive protein, bacterial superinfections, interventions, or survival in patients with severe COVID-19. PCSK9 regulates circulating cholesterol levels, and 15 cholesteryl ester (CE) species and free cholesterol (FC) were quantified by direct flow injection analysis using a high-resolution hybrid quadrupole-Orbitrap mass spectrometer. Most CE species with shorter fatty acid chains were decreased in severe compared to moderate COVID-19, and none of the CE species were correlated with PCSK9 in patients with severe COVID-19. Levels of all CE species negatively correlated with C-reactive protein in severe COVID-19 patients. Notably, FC was induced in severe compared to moderate COVID-19. The FC/CE ratio correlated positively with inflammatory markers and was associated with non-survival. The current study suggests that the imbalance between CE and FC levels is associated with disease severity and mortality in patients with COVID-19. [ABSTRACT FROM AUTHOR]

It is more difficult to accurately control the cycle fuel mass of a gasoline engine as the injection pressure increases, and the difference in the injection mass flow will become intense due to the machining error of GDI injector structural parameters. In order to guarantee the uniform cycle fuel mass of the GDI injector, this paper investigates the effect of the inlet orifice on the injection mass flow and the sensitivity of inner-flow characteristics in the GDI injector nozzle to the inlet orifice radius by the single factor analysis method. The results show that the local resistance of the injector nozzle will decrease and the discharge coefficient will rise due to the increase in the inlet orifice radius; the sensitivity of cycle fuel mass to the inlet orifice radius is most strong at r = 0.02 mm, and its accuracy should be improved when grinding the chamfer of the nozzle inlet; the sensitivity coefficient of the inlet orifice radius will rise up, and the machining accuracy of the inlet orifice radius should be improved as there is an increase in injection pressure. [ABSTRACT FROM AUTHOR]

A novel antipsychotic medication named brexpiprazole (BRX) is currently employed for the treatment of schizophrenia and other psychotic disorders. Because BRX's molecular structure includes a benzothiophene ring, it natively fluoresces. To detect BRX with precision and speed, a flow injection-fluorometric method, which is both sensitive and selective, is recommended. The fluorescence detection was conducted at 364 nm following excitation at 326 nm to capture the strong intrinsic fluorescence of BRX. The carrier solution employed was a mixture of phosphate buffer (pH 4, 10 mM) and acetonitrile (50: 50, v/v), with a flow rate of 0.5 mL min− 1. The calibration curve, based on peak areas, exhibited linearity within the concentration range of 20–350 ng mL− 1, with a remarkable correlation coefficient (r2) of 0.9999. The limit of quantitation was 9.7 ng mL− 1, and the limit of detection was found to be 3.2 ng mL− 1. This method was applied to quantify BRX in Neopression® tablets, achieving recovery within an acceptable range without interference from the tablet's additives. Additionally, the proposed approach was successfully utilised to quantify the drug in spiked human plasma. The approach underwent validation following ICH requirements. [ABSTRACT FROM AUTHOR]

This study presents a novel method for separating asphaltene from crude oil at room temperature, eliminating the need for heating or refluxing. Traditional methods often suffer from high energy consumption, costly equipment, and safety risks associated with flammable steam. This research focuses on deasphalting heavy crude oil from southern Iraq, containing 3.934 wt.% of asphaltene. Using a lab-made flow injection analysis system, 27 experiments were conducted, varying solvent flow rates (10 mL/min to 50 mL/min), mixing coil lengths (200 cm to 300 cm), and combinations of aromatic and aliphatic solvents. An optimal design (custom) and response surface method (RSM) were employed to pinpoint the best conditions. The optimal deasphalting process involved a solvent flow rate of 50 ml/min, a 300 cm mixing coil, and a xylene/n-heptane (1:10 vol/vol) solvent blend. Statistical analysis confirmed the significance of parameters, encompassing single parameters, interactions, and quadratic effects, all with pvalues under the 0.05 confidence level. The efficiency of the deasphalting procedure was assessed practically and theoretically, yielding efficiency percentages of 71.97% and 73.48%, respectively, for asphaltene extraction. This innovative method offers a promising solution for efficient and safe asphaltene separation from crude oil without the need for energy-intensive processes. [ABSTRACT FROM AUTHOR]

This paper compares materials potentially suitable for preparing solid reference electrodes, which could be used in miniaturized flow electrochemical cells. The tested electrodes are based on Sb, Bi, Pd, Pt, and Ag. The stable potential of the reference electrodes was maintained by the pH of the electrolyte, except for the AgCl electrode, whose potential was given by the concentration of chlorides. The performance of the reference electrodes was evaluated through a series of experiments focusing on potential dependences, long‐term and short‐term stability, cyclic voltammetry, and flow injection analysis with amperometric detection. Potentiometric experiments showed that Sb‐based electrodes had the closest slope to theoretical values with minor changes over five weeks. Theory‐consistent results of potential dependence were also observed for AgCl electrodes. The results of the voltammetric and flow amperometric experiment suggest that Sb‐based reference electrodes are the most suitable tools for electrochemical measurement. AgCl electrodes are limited by the necessity of maintaining a high chloride concentration. Bi‐based and PdH electrodes provide unstable results, the latter particularly due to hydrogen desorption. Although able to provide the stable potential to some extent, Pt electrodes are not suitable as the reference electrodes due to the deformation of mainly hydrodynamic voltammograms. [ABSTRACT FROM AUTHOR]

Manganese is considered an emerging pollutant and it is perceived as a potential threat to human health and aquatic ecosystems. The need to determine and monitor the presence of Mn in environmental water requires increasingly precise and accurate chemical analytical techniques that provide reliable information to take timely measures in the event of potential environmental contingencies. The automation by flow analysis technique has allowed analytical procedures to isolate and preconcentrate manganese in environmental water samples. Additionally, it brings forth benefits such as greatly enhancing the sample processing capacity and a reduced time and reagent usage, leading to cost savings and minimized waste production, thereby aligning with the principles of green chemistry. In this review, a recent report of some flow analysis techniques (FIA, rFIA, SIA, MSFIA, LOV, and MPFS) is presented, highlighting the trend of automation, whose portability and miniaturization allow for complete in situ analysis. There are two remarkable analytical features from the studies evaluated here, which are sample throughput and accuracy, with a maximum processing time of 120 samples h−1 and an accuracy of 98%. The implementation of flow analysis techniques offers several advantages, such as miniaturization and portability. The discussed methodologies achieved limits of quantification as low as 0.26 µg L−1, enabling environmental monitoring that can easily detect the reference value of 0.05 mg L−1, established by the WHO and the EPA. [ABSTRACT FROM AUTHOR]

A specific feature of mushrooms (including those of the genus Pleurotus) is their natural ability to absorb and accumulate many chemical substances present in their immediate environment, which makes them an excellent natural sorption material. Hence, fruiting bodies of mushrooms have been recognized for years as excellent indicators of the environment, reflecting its current state. Nevertheless, mushrooms can accumulate both health-promoting substances, such as bioelements, and toxic substances, such as heavy metals and organic compounds, including bisphenol A® (BPA). This organic chemical compound in the phenol group, although it has been withdrawn in the EU since 2010, is widely present in the environment around us. In the present experiment, we aimed to determine the effect of adding BPA to liquid media for in vitro cultures of Pleurotus spp. The biomass increases were determined. Moreover, the degrees of adsorption and desorption of BPA from the obtained freeze-dried biomass in two different environments (neutral and acidic) were determined as a function of time. This is the first study to determine the bioavailability of adsorbed BPA in obtained biomass by extracting the mycelium into artificial digestive juices in a model digestive system. BPA was added to the liquid Oddoux medium in the following amounts: 0.01, 0.5, and 0.5 g/250 mL of medium. The amounts of adsorbed and desorbed BPA were determined by flow injection analysis (FIA) with amperometric detection. The addition of BPA to the substrate reduced the biomass growth in each of the discussed cases. BPA adsorption by the mycelium occurred at over 90% and depended on the morphology of the mushroom (structure, surface development, and pore size). BPA desorption depended on the pH of the environment and the desorption time. Mushrooms are an excellent natural remedial material, but BPA is extracted into artificial digestive juices; therefore, consuming mushrooms from industrialized areas may have health consequences for our bodies. [ABSTRACT FROM AUTHOR]

Nitrate (NO3−) contamination from agricultural and industrial waste affects environmental water quality and can cause severe diseases if consumed in drinking water. Therefore, the detection of NO3− is a necessary precaution. This work describes the development of an electrochemical sensor for NO3− detection that combines the advantages of ordered mesoporous carbon (OMC) and copper foam (Cu foam) on a glassy carbon electrode (Cu foam/OMC/GCE). The large surface area, uniform pore structure, and large pore volume of OMC supported the electrodeposition of Cu foam to create a highly porous electrocatalytic structure for NO3− reduction. Under optimal conditions, the developed electrochemical sensor exhibited linearity from 1.0 μM to 5.0 mM and a detection limit of 1.0 μM (S/N=3). Moreover, the proposed electrochemical sensor exhibited acceptable selectivity, and good stability and reproducibility. The developed sensor detected NO3− in drinking water samples with recoveries of 88.2±0.9 to 112.5±6.3 %. [ABSTRACT FROM AUTHOR]

Metabolomics, with its wealth of data, offers a valuable avenue for enhancing predictions and decision-making in diabetes. This observational study aimed to leverage machine learning (ML) algorithms to predict the 4-year risk of developing type 2 diabetes mellitus (T2DM) using targeted quantitative metabolomics data. A cohort of 279 cardiovascular risk patients who underwent coronary angiography and who were initially free of T2DM according to American Diabetes Association (ADA) criteria was analyzed at baseline, including anthropometric data and targeted metabolomics, using liquid chromatography (LC)–mass spectroscopy (MS) and flow injection analysis (FIA)–MS, respectively. All patients were followed for four years. During this time, 11.5% of the patients developed T2DM. After data preprocessing, 362 variables were used for ML, employing the Caret package in R. The dataset was divided into training and test sets (75:25 ratio) and we used an oversampling approach to address the classifier imbalance of T2DM incidence. After an additional recursive feature elimination step, identifying a set of 77 variables that were the most valuable for model generation, a Support Vector Machine (SVM) model with a linear kernel demonstrated the most promising predictive capabilities, exhibiting an F1 score of 50%, a specificity of 93%, and balanced and unbalanced accuracies of 72% and 88%, respectively. The top-ranked features were bile acids, ceramides, amino acids, and hexoses, whereas anthropometric features such as age, sex, waist circumference, or body mass index had no contribution. In conclusion, ML analysis of metabolomics data is a promising tool for identifying individuals at risk of developing T2DM and opens avenues for personalized and early intervention strategies. [ABSTRACT FROM AUTHOR]

Trace elements play crucial roles in cellular biology. Their improper homeostasis may contribute to the progress of eye diseases, exacerbated during ageing. The retinal pigment epithelium (RPE) is progressively deteriorated during age-related neurodegeneration and metal homeostasis may be compromised. In this study, elemental mass spectrometry (MS) was combined with cellular and molecular biology techniques to identify changes in trace elements during the in vitro degeneration of human RPE cells. Cells were collected at 21, 91, and 133 days and processed for RNA sequencing; Ca, Na, P, Mg, and Cu quantification by flow injection analysis and inductively coupled plasma–MS; and protein analysis by immunocytochemistry. Four-month-old RPE cultures showed depigmentation, impaired barrier function, and antioxidant protection, manifesting signs of epithelial-to-mesenchymal transition. Na and P significantly increased in the cytosol of degenerated RPE cells (from 15 ± 20 to 13495 ± 638 ng·µg−1 and from 30.6 ± 9.5 to 116.8 ± 16.8 ng·µg−1, respectively). Mg decreased in both the cytosol and insoluble fraction of cells (from 2.83 ± 0.40 to 1.58 ± 0.56 ng·µg−1 and from 247.57 ± 11.06 to 30 ± 8 ng·g−1, respectively), while P and Cu decreased in the insoluble fraction after 133 days in culture (from 9471 ± 1249 to 4555 ± 985 ng·µg−1 and from 2251 ± 79 to 1054 ± 235 ng·g−1, respectively), along with changes in metal-dependent antioxidant enzymes and Cu transporters. This RPE model reflected metal homeostatic changes, providing additional perspectives on effects of metal regulation during ageing. [ABSTRACT FROM AUTHOR]

The combination of flow injection technique and spectrophotometric detection can be employed for the rapid and low-cost methods for antibiotic assay. In this work, two flow injection analysis (FIA) systems, normal and reverse (nFIA and rFIA), combined with UV-Vis spectrophotometric technique were used for amoxicillin determination in its pure and pharmaceutical preparations. A colorimetric coupling reaction between amoxicillin and diazotized p-toluidine produced a bright yellow azo dye and quantified at a maximum wavelength of 426 nm. For nFIA and rFIA procedures, the amoxicillin calibration graphs had an RSD of less than 2% and were linear in the ranges of 5-200 and 1-140 µg/mL, respectively. The limits of detection and quantification were 1.41 and 4.71 µg/mL of amoxicillin for nFIA and 0.39 and 1.31 µg/mL for rFIA, respectively. The physical and chemical factors that could influence color sensitivity were investigated. Various commercial formulations containing different amounts of amoxicillin were successfully tested using the developed approaches, which demonstrated to be easy, rapid, reproducible, and interference-free. [ABSTRACT FROM AUTHOR]

Bisphenol A (BPA) has been classified as an endocrine-disrupting substance that may cause adverse effects on human health and the environment. The development of simple and sensitive electrochemical biosensors is crucial for the rapid and effective quantitative determination of BPA. This work presents a study on electrochemical sensors utilizing gold nanoparticle-modified multi-walled carbon nanotubes (CNT/AuNPs). Glassy carbon electrodes (GCEs) and screen-printed electrodes (SPEs) were conveniently modified and used for BPA detection. AuNPs were electrodeposited onto the CNT-modified electrodes using the galvanostatic method. The electrodes were properly modified and characterized by using Raman spectroscopy, cyclic voltammetry (CV), and electrochemical impedance analysis (EIS). The electrochemical response of the sensors was studied using differential pulse voltammetry (DPV) and constant potential amperometry (CPA) for modified GCE and SPE electrodes, respectively, and the main analytical parameters were studied and optimized. Problems encountered with the use of GCEs, such as sensor degradation and high limit of detection (LOD), were overcome by using modified SPEs and a flow injection device for the measurements. Under this approach, an LOD as low as 5 nM (S/N = 3) was achieved and presented a linear range up to 20 μM. Finally, our investigation addressed interference, reproducibility, and reusability aspects, successfully identifying BPA in both spiked and authentic samples, including commercial and tap waters. These findings underscore the practical applicability of our method for accurate BPA detection in real-world scenarios. Notably, the integration of SPEs and a flow injection device facilitated simplified automation, offering an exceptionally efficient and reliable solution for precise BPA detection in water analysis laboratories. [ABSTRACT FROM AUTHOR]

A novel and highly sensitive flow injection method was developed for the determination of Mebeverine. The method is based on the formation of an ion pair compound between Mebeverine hydrochloride and calcium hexacyanoferrate in an ammonium chloride medium, resulting in the formation of a whitish-yellow precipitate complex. The analysis was performed using a homemade NAG-4SX3-3D triple flow cell CFIA Analyzer. The experimental parameters were studied to optimize both the chemical and physical aspects of the method. The linear working range was obtained to be 0.01-40 mM, with an impressive correlation coefficient (r) of 0.9907. The limit of detection (LOD) was determined to be 0.349 µg/150 µl, and the repeatability of the method (RSD%) was demonstrated to be less than 1.5%. To further evaluate the performance of the newly proposed method, a comparison was conducted using the standard addition method in conjunction with a classical method. Overall, the developed flow injection method offers simplicity, sensitivity, and reliable analytical performance for the determination of Mebeverine, making it a promising alternative to the classical method. [ABSTRACT FROM AUTHOR]

This study utilizes the mold flow analysis technique of the injection compression molding (ICM) process, combined with the Taguchi--gray relational analysis (GRA), for process optimization analysis on the roundness of the lens holes and the flatness of the lens mount in a 4 x 4 planar multilens array mount. After manufacturing simulation analysis, the eccentricity and tilt information of the lens mount was further evaluated optically through spot diagram analysis upon inserting the same glass lenses. The results showed a positive correlation trend between roundness and flatness in structural deformation analysis, indicating that improving the overall flatness of the lens mount can enhance the roundness of the lens holes. In optical analysis, better improvements in the lens tilt angle were achieved through GRA. In conclusion, aiming to simultaneously improve the roundness of the lens holes and the overall flatness of the lens mount, the Taguchi--GRA method can achieve the optimization objectives. In terms of optical performance, by optimizing for roundness, it is possible not only to reduce the diameter of the light spot but also to simultaneously reduce the offset displacement of the light spot center on the screen. The method proposed in this paper can serve as an analytical model for the design and fabrication of plastic multilens mount. [ABSTRACT FROM AUTHOR]

High-resolution, autonomous monitoring of phosphate and silicate in the marine environment is essential to understand their complex dynamics and implications for the functioning of marine ecosystems. In the absence of dependable reagent-less sensors for these nutrients, leveraging established colorimetric techniques using miniaturized analyzers, such as programmable Flow Injection (pFI), offers the best immediate solution to meet oceanographic accuracy and precision standards. In this work, we further optimize the phosphomolybdate and silicomolybdate assays recently adapted for use with pFI, laying the groundwork for the technique's use for long-term, autonomous operations. For both assays, we show that only a narrow range of acidities and molybdate concentrations can maximize sensitivity while minimizing salt effects. In addition, we demonstrate the stability of our optimized colorimetric reagent formulations, ensuring that analytical sensitivity remains within 10% of initial levels for at least 35 days of continuous use. We then applied our optimized protocols to produce oceanographically consistent phosphate and silicate profiles at the Hawaii Ocean Time Series (HOTS) and Southern Ocean Time Series (SOTS), respectively, which compared favorably against a reference method and historical data. Using certified reference materials for nutrients in seawater, we show that our pFI protocols, optimized for long-term operations, achieve a shipboard precision better than 6% and a relative combined uncertainty (k=1) of 4.5% for phosphate (0.45 - 2.95 µmol L-1) and 6.2% for silicate (2.2 to 103 µmol L-1). To demonstrate pFI's potential as a versatile tool for autonomous monitoring, we report a five-day hourly phosphate time series at a coastal shore station in central California (n=121 analyses), examine phosphate uptake by seaweed at five-minute intervals at a seaweed aquaculture facility (n=103), and discuss a unique, high-resolution surface silicate transect spanning multiple frontal zones in the Australian sector of the SouthernOcean (n=249). These data, obtained using a commercially available pFI analyzer, confirm that pFI is a viable technology for autonomous monitoring of phosphate and silicate, paving the way for more ambitious, long-term deployments in a variety of settings. [ABSTRACT FROM AUTHOR]

In general, concepts such as chemical equilibria and classical analytical chemistry, as well as instrumental methods such as potentiometry and flow injection analysis (FIA), are taught separately in the curricula of chemistry-related degree programs. However, FIA provides an opportunity to connect all of these important topics. This article shows how simple experiments can be used to link the fundamentals of FIA and potentiometry to the fundamentals of chemical equilibria and teach them in a sustainable way. The experiments were designed for undergraduate environmental science students with basic knowledge of chemical equilibria and classical analytical chemistry and minimal knowledge of electrochemistry. However, they can also be integrated into various courses on instrumental analysis in chemistry-related degree programs. [ABSTRACT FROM AUTHOR]

Quantum chemistry calculations were performed to elucidate the reaction sites and degradation routes of dexamethasone. Flow Injection Analysis Electrospray Fourier‐Transform Ion Cyclotron Resonance Mass Spectrometry (FIA‐ESI‐FTCIR‐MS) was used to identify dexamethasone and its byproducts in Mexico City's wastewater, guided by results from ab‐initio calculations on the bond energy analysis and thus propose possible degradation routes. Products of hydroxylation/reduction, decarbonylation/formylation and defluorination reactions were identified. The results of this study contribute to the identification of the degradation products of drugs commonly used in the treatment of COVID‐19 in urban areas. Through wastewater analysis and computationally assisted Mass‐Spectrometry techniques, an alternative approach is presented to identify byproducts in complex matrices when analytical standards are unavailable or in case of limited understanding on the stability of the degradation byproducts in aqueous medium. [ABSTRACT FROM AUTHOR]

Ozone-based chemiluminescence detection (CLD) has been widely applied for determining nitric oxide (•NO) and its derived species in many different fields, such as environmental monitoring and biomedical research. In humans and animals, CLD has been applied to determine exhaled •NO and •NO metabolites in plasma and tissues. The main advantages of CLD are high sensitivity and selectivity for quantitative analysis in a wide dynamic range. Combining CLD with analytical separation techniques like chromatography allows for the analytes to be quantified with less disturbance from matrix components or impurities. Sampling techniques like microdialysis and flow injection analysis may be coupled to CLD with the possibility of real-time monitoring of •NO. However, details and precautions in experimental practice need to be addressed and clarified to avoid wrong estimations. Therefore, using CLD as a detection tool requires a deep understanding of the sample preparation procedure and chemical reactions used for liberating •NO from its derived species. In this review, we discuss the advantages and pitfalls of CLD for determining •NO species, list the different applications and combinations with other analytical techniques, and provide general practical notes for sample preparation. These guidelines are designed to assist researchers in comprehending CLD data and in selecting the most appropriate method for measuring •NO species. [ABSTRACT FROM AUTHOR]

An amperometric bienzymatic biosensor was developed for the determination of aspartame in a flow injection analysis (FIA) system, consisting of two enzyme reactor columns packed with immobilized α-chymotrypsin (CHY) and alcohol oxidase (AOX) beads and a hydrogen peroxide electrode, connected in series. The CHY and AOX were separately immobilized on glutaraldehyde (GA)-activated beads through covalent bonding. The biosensor fabrication and operational conditions were optimized. The optimal fabrication conditions were: 2% GA with 120 min activation time; and 250 U/mL CHY and 100 U/mL AOX, with 180 min enzyme immobilization time. The optimal operational conditions were a flow rate of 0.5 mL/min and pH 8.0 at room temperature. The developed biosensor showed linearity over the aspartame concentration range 0.01–1.2 mM, with a detection limit of 0.005 mM. The developed biosensor was satisfactorily applied for detecting aspartame in beverage samples without any excessive pretreatments. [ABSTRACT FROM AUTHOR]

In this paper, a simple, sensitive, and precise flow injection system was optimized and applied to ascorbic acid determination with a carbon paste electrode modified with the Schiff base copper complex. The modified sensor showed increased sensitivity toward ascorbic acid oxidation with a decrease of oxidation potential by 200 mV. Under optimized flow parameters, working potential, gasket thickness, sample and reaction coil volumes, and flow rate, the developed flow system gave a linear response from 5 to 75 μmol/L of ascorbic acid. The calculated limit of detection was 4.5 μmol/L, calculated as 3σ/s which corresponds to the absolute value of 40 ng for the 50 μL sample coil. The precision for six consecutive injections of 5 and 75 μmol/L ascorbic acid solutions was determined as a relative standard deviation of 5.8 % and 1.5 %, respectively. The flow injection system enabled up to 120 analyses per hour. An optimized flow system was applied to the determination of ascorbic acid in dietary supplements, after simple preparation. [ABSTRACT FROM AUTHOR]

This study included a new, simple, fast, and sensitive new microfluidic sensor for the determination of total antioxidant (TAC) in patients with diabetic nephropathy and control then compare results with the conventional method (spectrophotometer technique). This method is dependent on the reduction of Cu2+ into Cu1+ by the action of antioxidants that are existing in the sample and chelating factor like neocuproine that produced complex colors. The spectrophotometry method was utilized to measure the absorbance of TAC at 450 nm in patients with diabetic nephropathy and control, also measured of TAC by using a innovative microfluidic system that contain a novel double split ring resonator sensor, after that compare outcomes between both techniques that indicated no significance differences in result of TAC after measured by spectrophotometer and new microfluidic sensor. [ABSTRACT FROM AUTHOR]

Laser engraving is a convenient, fast, one-step, and environmentally friendly technique used to produce more conductive surfaces by local pyrolysis. The laser's thermal treatment can also remove non-conductive materials from the electrode surfaces and improve electrochemical performance. The improvement was assessed by electrochemical tools such as cyclic voltammograms and electrochemical impedance spectroscopy using [Fe(CN)6]3−/4− and dopamine as redox probes. The electrochemical results observed showed that a treated surface showed an improvement in electron transfer and less resistance to charge transfer. To optimize the electrode performance, it was necessary to search for the most favorable graphite mines and optimize the parameters of the laser machine (laser power, scan rate, and output distance). The resultant material was adequately characterized by Raman spectroscopy and scanning electron microscopy (SEM), where an irregular surface composed of crystalline graphite particles was noticed. Furthermore, as a proof-of-concept, it was applied to detect indapamide (IND) in synthetic urine by flow injection analysis (FIA), a diuretic drug often used by athletes to alter urine composition to hide forbidden substance consumption in doping tests. [ABSTRACT FROM AUTHOR]

Ammonium fluoride has been shown to improve sensitivity when using electrospray ionization (ESI) coupled with mass spectrometry (MS). Recent internal investigation furthered that claim, through the observation of improved sensitivity when analyzing steroid molecules. This work focuses on extending those observations to other small molecules to understand the impact ammonium fluoride has on detection sensitivity with optimized instrument conditions. Using conventional liquid chromatography ESI‐MS we investigated sensitivity differences between ammonium fluoride, formic acid, or ammonium hydroxide as mobile phase additives. Full source optimization was performed for nine compounds at three different organic concentrations (30%, 60%, or 90%) with formic acid, ammonium fluoride, and ammonium hydroxide adjustment. Optimization results were compiled to generate individual methods by compound, polarity, mobile phase, and organic concentration. Flow injection analysis was performed with fully optimized methods to compare compounds across different solvent systems under optimal conditions. Negative ESI data showed 2–22‐fold sensitivity improvements for all compounds with ammonium fluoride. Positive ESI data showed > 1–11‐fold improvement in sensitivity for four of seven compounds and no change for three of seven compounds with ammonium fluoride. Ammonium fluoride improved ESI− sensitivity for all compounds studied when using optimized source conditions. Investigation with ESI+ analyses showed mixed results, with four of seven compounds showing improvement and others showing equivalency or slight loss in sensitivity, suggesting potential sensitivity gains for some analogs with ESI+. [ABSTRACT FROM AUTHOR]

Manganese is considered an emerging pollutant and it is perceived as a potential threat to human health and aquatic ecosystems. The need to determine and monitor the presence of Mn in environmental water requires increasingly precise and accurate chemical analytical techniques that provide reliable information to take timely measures in the event of potential environmental contingencies. The automation by flow analysis technique has allowed analytical procedures to isolate and preconcentrate manganese in environmental water samples. Additionally, it brings forth benefits such as greatly enhancing the sample processing capacity and a reduced time and reagent usage, leading to cost savings and minimized waste production, thereby aligning with the principles of green chemistry. In this review, a recent report of some flow analysis techniques (FIA, rFIA, SIA, MSFIA, LOV, and MPFS) is presented, highlighting the trend of automation, whose portability and miniaturization allow for complete in situ analysis. There are two remarkable analytical features from the studies evaluated here, which are sample throughput and accuracy, with a maximum processing time of 120 samples h−1 and an accuracy of 98%. The implementation of flow analysis techniques offers several advantages, such as miniaturization and portability. The discussed methodologies achieved limits of quantification as low as 0.26 µg L−1, enabling environmental monitoring that can easily detect the reference value of 0.05 mg L−1, established by the WHO and the EPA.

Differential mobility spectrometry (DMS) is highly useful for shotgun lipidomic analysis because it overcomes difficulties in measuring isobaric species within a complex lipid sample and allows for acyl tail characterization of phospholipid species. Despite these advantages, the resulting workflow presents technical challenges, including the need to tune the DMS before every batch to update compensative voltages settings within the method. The Sciex Lipidyzer platform uses a Sciex 5500 QTRAP with a DMS (SelexION), an LC system configured for direction infusion experiments, an extensive set of standards designed for quantitative lipidomics, and a software package (Lipidyzer Workflow Manager) that facilitates the workflow and rapidly analyzes the data. Although the Lipidyzer platform remains very useful for DMS-based shotgun lipidomics, the software is no longer updated for current versions of Analyst and Windows. Furthermore, the software is fixed to a single workflow and cannot take advantage of new lipidomics standards or analyze additional lipid species. To address this multitude of issues, we developed Shotgun Lipidomics Assistant (SLA), a Python-based application that facilitates DMS-based lipidomics workflows. SLA provides the user with flexibility in adding and subtracting lipid and standard MRMs. It can report quantitative lipidomics results from raw data in minutes, comparable to the Lipidyzer software. We show that SLA facilitates an expanded lipidomics analysis that measures over 1450 lipid species across 17 (sub)classes. Lastly, we demonstrate that the SLA performs isotope correction, a feature that was absent from the original software.

A strategy to design an injection valve for a streamlined flow injection technique is described as speed and low-cost materials available in the environment for the determination of Pb(II) ion using the organic reagent 4-((4-methoxyphenyl)diazenyl)benzene-1,3-diol at a wavelength of 498 nm. The scope of the study is to find the optimal conditions, including the flow rate of the carrier, the dispersion coefficient, the length of the reaction coil, and the calibration drawing. The results showed that the optimum length of the reaction coil is 20 cm, and the optimum flow rate is 9.1 mL/min, which is equivalent to the pumping rate of 70 F/min. The range of linearity of the study was revealed by a calibration curve of 0.5–27 mg/L, slope = 1.507, correlation coefficient = 0.9995, the limit of quantitative (LOQ) = 0.088 mg/L, and limit of detection (LOD) = 0.026 mg/L. The system under study has a characteristic efficiency. The dispersion coefficient was calculated for concentrations of 10–15 mg/L Pb(II) ion. Furthermore, the accuracy of the flow injection technique in the estimation process was studied and compared with the Flame Atomic Absorption Spectroscopy (FAAS) technique.

A novel simple sensitive and effective on-line flow injection column preconcentration platform using poly-tetrafluoroethylene turnings as sorbent was developed prior to flame atomic absorption spectrometric (FAAS) determination of palladium in vehicle exhaust catalysts, hydrogenation catalysts and environmental water samples. The method is based on the sorption of palladium(II)-diethyldithiophosphate, which was found to be more effective than dithiocarbamate ones. Methyl isobutyl ketone (MIBK) was used as eluent prior atomisation and quantification. All parameters like pH, DDPA concentration, flow rates, preconcentration time that affect the sensitivity of the method as well as interferences of other metals were investigated in detail. The enhancement factor calculated as 114 for 60 s preconcentration time while the sampling frequency as 40 h−1. The detection limit was 0.9 μg L−1 and the relative standard deviation (RSD) was 2.8% at 20.0 μg L−1 concentration level. The accuracy of the proposed method was estimated by analysing certified reference material and spiked environmental samples. The analytical features of the method were compared with other on-line column preconcentration methods reported in the literature. [ABSTRACT FROM AUTHOR]

A precise, simple, and accurate continuous flow injection technique was used for the instantaneous estimation of bromhexine hydrochloride (BH-HCl) in tablet dosage form. The chemical and physical parameters of the reaction of BH-HCl with tetraphenylborate to produce a yellowish-white precipitate were determined using an ISNAG fluorimeter analyzer and diverging light at 90°. The calibration curve for BH-HCl was linear with correlation coefficients of 0.9994 and linearity percentage r²% = 99.87 over a concentration range of 0.01-20 mmol/L, L.O.D = 0.3610 µg/125µL (0.007 mmol/L), and RSD% less than 0.3% for 3 and 13 mmol/L (five replicates). This approach was efficiently used to estimate the levels of BH-HCl in two distinct pharmaceutical companies. When the newly developed method was compared with the turbidimetric method using a t-test and standard addition, it was discovered that there had not been any significant difference between the two approaches at the 95% level of confidence. [ABSTRACT FROM AUTHOR]

A new voltammetric method is proposed for high sensitive thiethylperazine (THP) determination, using a glassy carbon electrode modified with semi-graphitized carbon nanofibers/MnO nanocomposite (eCNF/MnO/GC). To the best of our knowledge, this is the first electrochemical assay of THP determination, and the first use of the eCNF/MnO as the electrode modifier. The proposed method using eCNF/MnO/GC is characterized by high repeatability and sensitivity of measurements, with the linearity of THP in the range from 0.05 to 2.2 µmol L−1. The lowest detection limit achieved on the eCNF/MnO/GC electrode for 30 s of preconcentration was 6.3 nmol L−1 THP in 0.05 mol L−1 acetate buffer of pH 5.6. The proposed method was successfully applied to highly sensitive THP determination in complex matrices, such as tablets and plasma with good recovery (98–103%). The RSD value obtained for THP measurement at a concentration of 0.1 µmol L−1 was 1.3%. Amperometric measurements of THP under the flow injection conditions were also performed to indicate the possibility of its fast and accurate determination (103% and 95% for unmodified and modified electrode, respectively), with the duration of single analysis of approx. 30 s. [ABSTRACT FROM AUTHOR]

Scopatizzo, belonging to the Cucumis melo L., is a local variety of Apulia (Southern Italy), which is consumed as unripe melon as an alternative of cucumber due to its better-quality profile and for the absence of cucurbitacins. The latter are tetracyclic triterpenes synthesized by some Cucurbitaceae species, known to confer an unpleasant taste to fruits and cause health problems. Following the discovery of Scopatizzo fruits with bitter taste, cucurbitacins were searched for in their ethanolic extract. Flow injection analysis with detection performed by atmospheric pressure chemical ionization-high resolution mass spectrometry provided evidence for the presence of at least four cucurbitacins, which were absent in typical, sweet-tasting fruits. Further insight into this discovery will be required in the near future to assess if the detection of cucurbitacins may mark the appearance of genotypes whose fruits have features not compatible with commercialization. [ABSTRACT FROM AUTHOR]

Introduction: mercury (Hg) accumulates in large predatory species in marine ecosystems, such as tuna, swordfish, or various sharks species. Objective: to validate, through additions, a method of atomic absorption spectroscopy with cold vapour and flow injection system for the measurement of total Hg in seafood products. Material and methods: a total of 18 samples of different seafood products were analysed, spiking them to 4 ranges: low (0.1 mg/ kg); intermediate (0.5 and 1.0 mg/kg) and high (2.0 mg/kg). These were digested in a microwave oven and analysed with an atomic absorption spectrometer. Results: the diversity of the samples and the good accuracy and precision of the results confirmed the selectivity of the method. The working range of the method was established between 0.10-0.32 mg/kg of Hg in the sample and the limit of quantification at 0.10 mg/kg. All calibration lines fitted the linear regression model with statistical significance (p < 0.05). The trueness was 4.28%; 3.20 %; 12.28 % and 0.84% respectively for the 0.1 mg/kg; 0.5 mg/kg; 1.0 mg/kg and 2.0 mg/kg ranges, respectively. The average recovery of the method was 102.54 %. Horrat reproducibility (HorratR) values were 0.41; 0.30; 0.37 and 0.66 and Horrat repeatability (Horratr) values were 0.48; 0.35; 0.11 and 0.47 for the 0.1 mg/kg; 0.5 mg/kg; 1.0 mg/kg and 2.0 mg/kg spiking ranges, respectively in each case. The relative uncertainty values in each range were lower than the fixed limit of 25 %. Conclusion: our method was validated by fulfilling the regulatory requirements and the previously established acceptance criteria. [ABSTRACT FROM AUTHOR]

The research developed an analytical methodology for the analysis of total polyphenols in wines, using a flow injection analysis system (FIA) with amperometric detection, using an electrode modified with multilayer carbon nanotubes. For this purpose, the procedure for the elaboration of MWCNTs dispersions, using polyethylenimine as dispersing agent and its use for the modification of glassy carbon electrodes, was initially evaluated. The processing conditions were: 0.50 mg-mL-1 nanomaterial concentration, 0.25% (m/m) PEI, 2000 J of dispersion energy in PEI, centrifugation (2500 rpm; 20 min) and finally, redispersion in water applying 2000 J of energy. These electrodes show lower oxidation potentials, higher peak intensity and lower I/C ratios than the unmodified electrodes. Finally, this FIA methodology was developed incorporating the optimized electrode [GCE(PEI-Water/MWCNTs)], in order to detect and quantify total polyphenols, obtaining improvements in stability, reproducibility, greater sensitivity and possibility of selective detection of these compounds, in the analysis of white wines made with two types of grapes: Verdejo and Airén. This developed methodology could provide additional information from electrochemical indices, generating an alternative analysis to spectrophotometric studies. [ABSTRACT FROM AUTHOR]

A new strategy integrating the straight synthesis of carbon dots (CDs) and their direct use for the determination of heavy metals by means of fluorescence quenching is presented. The proposal consists of a modular analyzer, which includes a low temperature co-fired ceramics (LTCC) microreactor for the synthesis of CDs and a cyclic olefin copolymer (COC) microfluidic platform, which automatically performs a reverse flow injection analysis (rFIA) protocol for the determination of heavy metal ions in water by CD fluorescence quenching. As a proof of concept, nitrogen-doped CDs were synthesized from acrylic acid and ethylenediamine (ED) with quantum yields (QYs) of up to 44%, which are selective to cobalt. With the described system, we synthesized homogeneous CDs without the need for further purification and with the minimum consumption of reagents, and optimized fluorescence measurements can be performed with freshly obtained luminescent nanomaterials that have not undergone decomposition processes. They have an average hydrodynamic diameter of 4.2 ± 0.9 nm and maximum excitation and emission wavelengths at 358 nm and 452 nm, respectively. The system allows the automatic dilution and buffering of the synthesized CDs and the sample prior to the determination of cobalt. The concentration of cobalt was determined with good sensitivity and a limit of detection of 7 μg·L−1 with a linear range of 0.02–1 mg·L−1 of Co2+. Spiked tap water and river water samples were analyzed, obtaining recovery from 98 to 104%. This demonstrates the potential of the equipment as an efficient on-site control system for heavy metal monitoring in water. [ABSTRACT FROM AUTHOR]

This study is mainly focused to obtain stable dimensions for plastic products used in manufacturing industries. A technique of microcellular foaming injection method was chosen with added chemical blowing agents to decrease the mass, clamping force, and cycle time. Mold flow analysis was run to compare the conventional plastic injection (KP) method with chemical foaming injection molding method using added TecoCell H1 (TH) and CS (TCS). The primary process conditions are considered as temperature of the mold, velocity of injection, pressure and time of holding, and cooling time. The experiments were carried under polymer material as (polypropylene) Moplen EP548P. The new chemical blowing agents TH and TCS, having different reactive material ratios (50% and 25% endothermic) and gas concentration ratios, were utilized at a rate of 1% by weight claiming to be a novel method for producing the parts with high efficiency. The results of both the flow analysis and the injection molding experiments demonstrate that, plastic samples produced by conventional plastic injection could be made approximately 7.5% lesser weight, with 33% lesser force of clamping, and a gain of cycle time nearly 15% by adding chemical blowing agents to the process. Topsis technique is carried for determining the best fabrication method. It was observed that, the injection molding method with Tecocell H1 (TH) chemical foaming agent exhibited better results in terms of less clamping force, reduced cycle time, and weight of the product. The experimental results are validated using the Topsis method and the results are satisfied. Hence, the chemical blowing agent Tecocell H1 (TH) can be applied as a foaming agent for manufacturing the plastic products and increase the efficiency of the production. [ABSTRACT FROM AUTHOR]

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Poultry litter on agricultural lands could introduce nitrogen (N), phosphorus (P), heavy metals in soil and ground water. Native vegetations were identified to assess efficacy for phytoremediation of nutrients and metals from soil and water. Objective was to measure capability of multi-year native species to remove metals, nutrients, and prevent Nitrate-N leaching below the rooting zone. Treatments were distributed in four replicates with/without fertilization. Suction lysimeters were installed at 30, 60, and 90-cm depths in 3 of 4 replicates. Species were identified, recorded, five specified cuttings sampled. Plant, soil, water samples were prepared and analyzed by spectroscopy. Nitrate-N extraction, nitrates in water samples were determined using flow injection analysis. Fertilized plots (NVM) had 39% more biomass yield than unfertilized plots (NVN). In plants, nutrient and metal concentrations varied significantly with 14% increase in Zn, 36% and 26% in K and Mg over NVN for first and second year. Uneven between NVM and NVN, topsoil had higher values for most nutrients and metals. Largest P and (NO3−)−N in plant and water were observed from NVM. Cultivation of native vegetation appears to be an effective approach for remediation of excess nitrates-N, P, heavy metals from surface and sub-surface zones of the soil. Native vegetation has been used for soil fertility, specific reasons like the removal of pesticides or agrochemicals, and other chemical related exposures. Studies on the use of native vegetation for phytoremediation on agricultural lands are uncommon. This research looked at the capability of native vegetation of different species as a viable tool for the remo+val of excess nutrients and heavy metals from agricultural lands. Results indicated native vegetation can take up significant amounts of excess nutrients from soils, proportional to their biomass accumulation. Native Vegetation was therefore found to be a nutrient sink, capable of removing excess nutrients/metals from the soil. [ABSTRACT FROM AUTHOR]

This work describes the development of a fast, precise and reliable voltammetric method for the quantification of indapamide, an orally active diuretic sulfonamide used for hypertensive treatment. This compound acts inhibiting sodium reabsorption and increasing the elimination of water. This characteristic was responsible for its banishment by the International Olympic Committee since 1999. The study begins by finding an adequate potential range (−0.20 to 0.30 V) to avoid poisoning the working glassy carbon electrode (GCE) in phosphate buffer 0.10 mol L−1 (pH=12.0). Utilizing flow injection analysis, linear responses between 2.0 × 10−6 mol L−1 to 2.5 × 10−5 mol L−1 of indapamide (R2=0.995), and detection limit (LOD) 3.0 × 10−7 mol L−1 were obtained. This method was applied for the quantification of indapamide in tablets and in synthetic urine. The same flow system was used for the analysis of commercial drugs and the response obtained corresponded to 98 % of the concentration indicated on the drug label. These tablets were also analyzed by high performance liquid chromatography (HPLC), obtaining a recovery of 103 % and LOD 4.0 × 10−7 mol L−1. The velocity of analysis using flow methods compares advantageously to the classical chromatographic methods. For synthetic urine, linear responses were obtained in samples spiked in the region from 5.0 × 10−6 mol L−1 to 30 × 10−6 mol L−1 (R2=0.991) and LOD 3.0 × 10−7 mol L−1. [ABSTRACT FROM AUTHOR]