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A particular attention should be paid to isolation, characterization, and assessment of bioactive flavonoids, especially for anti-arthritic activity. The slurry of adsorbent (silica gel; 60–120 lattice) was blended in n-hexane to form a uniform slurry, and this was then employed as a fixed-stage adsorbent. Butanolic solution (10 g) was dissolved in the minimum volume of butanol, and then adsorbed on silica gel (60–120 mesh) while still wet. The wet powder was then dried, and the separated liquid phase was collected and applied to the column to try to isolate possible phytoconstituents. A whole plate full of fractions was monitored simultaneously on a TLC plate with a mixture of chloroform:methanol:water (68:30:02) as the solvent system. Six fractions (F1-F6) were generated after the colours of F1 and F2 were mixed next to each other, and after Rf was discovered in F3. A separate group of six animals was created for the survey, which was made up of five treatment groups and one control group. It was concluded that yellow crystalline solid luteolin was obtained as a result, with the Shinoda test confirming that it was a flavonoid. The absorption of luteolin was discovered to be in an aqueous alkaline solution. There were five different resonances, occurring at different frequencies, in the 400 MHz 1H NMR spectrum: 7.00 (d, J = 13.5 Hz, 2H), 6.73 (s, 1H), 6.56 (s, 1H), 6.18 (s, 1H), 6.05 (s, 1H), 4.78 (s, 1H), 4.24 (s, 1H), 3.81 (s, 1H) (s, 1H). Inhibiting arthritic inflammation at doses of 40 mg/kg (luteolin) was significant (P

Healthcare-associated infections can occur and spread through direct contact with contaminated fomites in a hospital, such as mobile phones, tablets, computer keyboards, doorknobs, and other surfaces. Herein, this study shows a transparent, robust, and visible light-activated antibacterial surface based on hydrogen bonds between a transparent silica-alumina (Si-Al) sol-gel and a visible light-activated photosensitizer, such as crystal violet (CV). The study of the bonding mechanisms revealed that hydrogen bonding predominantly occurs between the N of CV and Al-OH. Apart from CV, Si-Al can be combined with a variety of dyes, highlighting its potential for wide application. The Si-Al@CV film selectively generates singlet oxygen using ambient visible light, triggering potent photochemical antibacterial performance against Gram-positive and Gram-negative bacteria. Additionally, the Si-Al@CV film is stable even after mechanical stability tests such as tape adhesion, scratch, bending, and water immersion.

Polychlorinated naphthalenes (PCNs) have a structure similar to that of polychlorinated biphenyls (PCBs) and represent a new type of persistent organic pollutants (POPs) that are widely present in the environment and biological communities. PCNs can migrate and transform via different environmental media, which severely affects the health of humans and organisms. Researchers have devoted considerable focus on ambient air pollution. Although the current ambient air quality has not yet limited the concentration of PCNs, the Stockholm Convention has required parties to prohibit and eliminate their production and use. As one of the contracting parties, China is obligated to improve its environmental monitoring. In other words, the development of a method for monitoring PCNs in ambient air is important for understanding ambient air quality and safeguarding human health. PCNs are generally present at trace levels (pg/m

The synthesis of silica gel nanostructures and loading it with copper specie via a hydrothermal process were performed. The sample is treated with an amino-functional reagent 3-aminopropyl triethoxysilane (APTES). The products were characterized by X-ray diffraction (XRD), FT-IR, scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy-dispersive spectroscopy (EDS), TGA/DSC measurements, and X-ray photoelectron spectroscopy (XPS). The photocatalytic activities of the nanostructures were studied for degradation of methylene blue dye (as a classic dye contaminant) in aqueous solution utilizing visible light source. The results displayed that the sample treated with APTES is much more effective in photocatalytic degradation of methylene blue. This modified catalyst could eliminate methylene blue dye (50 mL, 18 µg mL

We describe a novel strategy to increase the unit-time-productivity of flow synthesis by using hierarchical bimodal porous silica gel (HBPSG) supported palladium column reactors. Because HBPSG has a significantly large surface area, the column reactors have low pressure drop, enabling high-volume production. We demonstrated flow synthesis of the precursor of adapalene, a pharmaceutical compound, at 5 g/h which is over 10-fold greater productivity than previous approaches.

This contribution provides an overview of the performance and retention characteristics of high-performance layers in the form of precoated plates for thin-layer chromatography. The dominant stationary phases are based on silica gel and chemically modified forms of silica gel with alkylsiloxane-bonded, 3-cyanopropylsiloxane-bonded, 3-aminopropylsiloxane-bonded, and spacer bonded propanediol surface treatments. Cellulose and esterified forms of cellulose represent minor use by comparison. Stationary phases for enantiomeric separations are largely based on the use of esterified forms of cellulose and reversed-phase layers impregnated with copper(II) complexes for ligand exchange chromatography. Sorbent properties that contribute to the performance of particle-packed layers are identified and the retention characteristics of the different sorbent types discussed.

In this study, a description was given for the adsorbent CaSiO3 for allure proximate examination and determination like particle density, main part density, and porosity analysis. This is performed before management of batch adsorption experiments. Both kinetics and balance studies for the adsorbent were examined. The influences of various process parameters like lead concentration, pH, adsorbent dosage, and contact temporal length for process removal were explored. The removal efficiency of CaO from eggshell was enhanced to increase after mixing it with silica coagulate compared with added scholar’s findings for the same limit. The maximum removal efficiency (99.58%) was obtained by limiting the pH, adsorbent dosage, initial lead concentration, and contact time at 4, 1.8 g, 35 g/L, and 140 minutes, respectively. Thus, blending CaO from eggshells with silica gel can increase the adsorption competency of CaO. Lead removal is well integrated into the Langmuir isotherm model with an equivalent factor of 0.991. The kinetic data of adsorption fit well into a pseudo-first-order model with a correlation coefficient of 0.90111. The pseudo-second-order model was the rate-determining step involved in the lead adsorption process for calcium silicate (CaSiO3) adsorbents.

Abstract: A broad class of dihydroxyarenes were easily oxidized by aerobic oxygen to quinone products in excellent yields under the catalytic effect of polymer-supported RuII-Pheox/silica-gel catalyst. By using this combined catalyst, hydroquinone and catechol derivatives with electron-donating groups were easily oxidized by molecular oxygen to quinone products in 90% to >99% yield, while in the case of electron-withdrawing group, only 70% was obtained. The biologically useful 1,4-Naphthoqinone products were obtained in 83% to 90%. The catalyst was easily obtained and reused many times without a significant decrease in reactivity. Interestingly, a sample of industrial water contaminated with phenolic compounds was subjected to aerobic oxidation by using this catalyst, and the resultant quinones were detected within one day and the catalyst was removed and reused several times with different contaminating samples with the same efficiency. Other catalytic oxidations by using this promising catalyst were investigated.

A novel method was developed to determine six triazine herbicides from brown sugar samples using matrix solid-phase dispersion (MSPD) based on silica gel impregnated with deep eutectic solvent (DES) followed by high-performance liquid chromatography with photodiode array detector (HPLC/PDA). Several factors involved in the MSPD procedure such as DES type, DES content in impregnated silica gel, adsorbent-to-sample mass ratio, type and volume of washing solvent, type and volume of eluent, and grinding time were screened using single-factor experiments and then optimized using Box-Behnken design to accomplish the highest recoveries. The above method demonstrated a good linear range (20-1000 μg kg

Heat-treated porous silica gel (HT silica gel) previously developed by our group has selectively adsorbed cationic peptides at a pH of 7. Therefore, we focused on the use of antimicrobial peptides (AMPs) as bioactive peptides (BPs). First, 32 AMPs and 32 randomly designed peptides were generated using Fmoc solid synthesis, and their adsorption ratio to HT-silica gel was investigated. Thirty two AMPs showed a relatively higher adsorption ratio of 58.8% compared to that of randomly designed peptides, which was 35.3%. Desorption conditions were investigated using Amyl-1-18 antimicrobial peptides. Next, pepsin hydrolysate from rice endosperm protein (REP) powder was prepared by ourselves. The REP hydrolysate containing dry matter (7.5 mg) was applied to the adsorption/desorption (AD) procedure using HT silica gel to obtain 1.6 mg of AD hydrolysate. When the two hydrolysates were subjected to mass spectrometry, 305 concentrated peptides were obtained. In total, 26 peptides with high content and high enrichment ratios were listed and synthesized. When the antimicrobial activity of these 26 peptides was evaluated using Cutibacterium acnes, five peptides consisting of 12-27 amino acids were identified as novel AMPs. Two of these peptides, which were derived from rice glutelin, showed antimicrobial activity against all four microbes, including Porphyromonas gingivalis, Escherichia coli, and Streptococcus mutans. In the present study, we showed that AMPs could be easily enriched from protein hydrolysate using HT silica gel. The adsorption/desorption procedure using HT silica gel was confirmed to be a useful tool for convenient BP separation.

As the bearer of wet load, the desiccant wheel determines the performance of the rotary wheel dehumidification system. In this study, a novel metal organic framework composite adsorbent desiccant wheel (MOF DW) was prepared by impregnating–spraying method. The complete rotary wheel dehumidification system was built to compare the dehumidification performance of MOF DW and commercially silica gel desiccant wheel (SG DW). The experimental results showed that increasing the rotation speed appropriately improves the utilization ratio of regenerative energy and dehumidification capacity of MOF DW at high ambient humidity ratio. The temperature rise at the inlet and outlet of MOF DW is lower than that of SG DW at low ambient humidity ratios, and the opposite is true at high ambient humidity ratios. In addition, the dehumidification capacity and coefficient of performance of the MOF DW increase by 40%–48% and 13%–19%, respectively, compared with those of the SG DW at the regeneration temperature of 50°C.

An HPTLC technique for simultaneous estimation of Valsartan and Hydrochlorothiazide in a pharmaceutical combination dose form must be verified for stability indication. For the separation of VAL and HTZ using TLC plates coated with aluminium supported silica gel 60 F254, a high-performance thin layer chromatographic (HPTLC) technique has been devised. For the separation of two medicines, a variety of mobile phases were tried and tested. It was decided to use chloroform: ethyl acetate: ethanol/tetrahydrofuran as the final mobile phase for analysis. 247 nm was chosen as the detecting wavelength for both compounds since it exhibited highest absorption. As per the ICH recommendations, the devised technique was validated. Under varied stress settings, medicines were forced to degrade, and the stability of pharmaceuticals was assessed using the HPTLC technique. The separation of VAL and HTZ using HPTLC was a great success. A low percent RSD was determined by testing a variety of factors, and the stability experiments showed that the medicines and degraded products could be separated with an acceptable percent drug recovery profile. Rapid, accurate, and reproducible are some of the characteristics of the devised technique, which proves its appropriateness for valsartan and hydrochlorothiazide stability assessment.

Novel HPLC method was developed for enantioresolution of tyrosine kinase inhibitor drug Ibrutinib (IBT). Separation and identification of IBT enantiomers was investigated using cellulose tris (3,5-dichlorophenylcarbamate) immobilized on silica gel (Chiral-pack-IC). Good baseline enantioseparation was achieved on Chiral-pack-IC under normal-phase condition composed of n-Hexane, ethanol in a ratio of 55 and 45 (%v/v) with 0.1% Diethyl amine and 0.3% Trifluoro acetic acid. Resolution between IBT and its enantiomer was above 4. The flow rate and column oven temperature were 0.9 mL/min and 30 °C respectively. Detection was carried out at 260 nm. Injection volume optimized was 10 µL. Developed method was validated in accordance with ICH guide lines for specificity, limit of detection, limit of quantification, linearity, accuracy, precision, ruggedness and robustness.

The current global concern related to ground water contamination especially fluoride (F- contamination has ascended in an increased exigence for effective adsorbents. In this study, we have used a surface altered pectin biopolymer with silica–gel (SG), and incorporation of cerium oxide (Ce@SG-Pec) for the application of F- adsorption studies from the aqueous systems. The temperature, contact time, absorbent dosage, pH, coexisting anions, and initial F- concentration are discussed. The isothermal and kinetic data were fitted to Temkin and pseudo-second-order model, respectively. Analysis of adsorptive thermodynamics showed that the adsorption process was endothermic, spontaneous, feasible, and chemisorption type of adsorption mechanism. The good adsorption is attributed to chemical adsorption through strong surface complexation of cerium and silicon with F- as well as the special structure of adsorbent. The surface analyses (BET and FESEM) had shown the decrease in pore size after the F- adsorption. Additionally, FTIR analyses supported the substantial role of ion–exchange and electrostatic interaction in the adsorption mechanism.

In the current paper, adsorbent based on silica gel L 40/100 modified with cetylpyridinium bromide was obtained. The presence of cetylpyridinium cations on the silica gel surface was confirmed by the diffuse reflectance infrared fourier transform spectroscopy method. The sorption conditions of erythrosine from dilute aqueous solutions with the proposed sorbent were studied and optimized. It is shown that the use of modified silica gel allows efficient (>95%) extraction of erythrosine from aqueous solutions. Under optimal sorption conditions (pH 7, sorbent dosage 0.1 g and sorption time is 15 min), the sorption capacity of modified erythrosine sorbents was determined. It is shown that, with increasing temperature, a change in the isotherm type from the H‑type to the L‑type is observed. This change can be explained by the aggregation of erythrosin in solution, which is a competitive sorption process. It was shown that adsorption isotherms were well described by the Langmuir equation. Thermodynamic studies have made it possible to establish the spontaneous sorption. The desorption of erythrosine from the surface of silica gel modified with cetylpyridinium bromide was studied. It is shown that when using solutions of sulfuric acid, sodium hydroxide and distilled water, desorption does not occur. It was shown that the most effective eluent is solution of sodium dodecylsulfate in alkaline medium, and desorption of erythrosine occurs due to the destruction of ion pairs of dye anions with cetylpyridinium cations fixed on the surface. The data obtained can then be used to develop a test system for determination of erythrosine via corresponding colorimetric scales or for quantitative solid phase extraction and adsorption-spectroscopic quantification of erythrosine in some real samples.

Various biogenic routes were explored for the synthesis and biocompatible use of iron nanoparticles. Nanoparticle synthesis using plant extracts gaining lots of research attention in recent decade due to the ease of availability, non-toxic nature and its efficient ability to act as reducing as well as capping agents. The present study focused on green environmentally feasible synthesis of iron nanoparticles using guava (Psidium guajava) leaf extract which serve as reducing as well as capping agent. For additional stabilization, the prepared nanoparticles were supported on silica gel. The sonochemically synthesized iron nanocomposite system for Cr(VI) removal has been explored first time for Cr(VI) adsorption. The derived nanoparticles were qualitatively analyzed using various instruments such as FTIR, XRD, SEM, and SEM–EDX. The synthesized material was used for the removal of Cr(VI) from the aqueous solution. Maximum removal of 100% was obtained at an optimized parameters (solution pH = 6.2; adsorbent dose = 4 g/L; contact time = 60 min; initial Cr(VI) conc. = 10 mg/L). The adsorption data agrees well with the Langmuir isotherm model, and kinetic investigation demonstrates that the Cr(VI) adsorption data are in consistent with the pseudo-second-order kinetic model.

Desiccant materials are recently discovered as a viable alternative in dehumidification technology due to their naturally hygroscopic qualities and minimal energy requirement. This paper discusses the performance of four brand samples of selected desiccants used for dehumidification. In this study, dehumidification ability and indoor air quality (IAQ) tests were carried out. The dehumidification ability test was conducted in a controlled environmental chamber at a temperature of 25°C, relative humidity of 70%, and air velocity of 2 m/s for 45-minute session. Meanwhile, the IAQ test was carried out in a naturally ventilated test room, and six IAQ parameters (relative humidity, air velocity, air temperature, particulate matter (PM10), airborne bacteria and carbon dioxide (CO2) were studied. The IAQ test was performed for five different conditions: control, application of brand samples A, B, C and D in the test room. From this study, it was found, brand A (0.6823 g/kg) and brand B (0.6849 g/kg) had a relatively good dehumidification ability during the 45-minute dehumidification ability test compared to brand C (0.3108 g/kg) and brand D (0.3982 g/kg). The IAQ test revealed that brand A had the biggest variation in indoor-outdoor relative humidity of 13.12%, while brand D had the smallest difference of 11.83%. Brand B had the highest average PM10 concentration of 0.037 μg/m3. The airborne bacterial count for all conditions had no statistical significance, indicating the application of desiccants were not effective in reducing airborne bacteria. From this study, it can be concluded that calcium chloride (brand A and B) samples performed better than silica gel (brand C and D) samples in terms of dehumidification ability and IAQ profile.

Organic acid doped polyaniline (PANI), hybrid with silica gel (SiG) and composites with metal primer have been prepared by chemical oxidative polymerization of double-distilled aniline in an acidic medium at 0-5 °C in an ice bath using ammonium persulphate as oxidant and p-toluene sulphonic acid (p-TSA) as the dopant. The anticorrosive property of PANI coatings containing alkyd primer, zinc chromate and silica gel was investigated. The coatings were characterized by FTIR spectroscopy, scanning electron microscopy and electrochemical impedance spectroscopy. The corrosion studies were carried out in a 3.5 wt% NaCl solution. On introduction of SiG, PANI, and PANI-SiG hybrid, the corrosion current decreased from 0.03626 μA to 0.007856 μA, 0.02042 μA, and 0.011 μA, respectively. The penetration rates calculated in mm/yr. for the composites: SiG/Primer, PANI/Primer and PANI-SiG/Primer were 0.430× 10-4, 1.110× 10-4, and 0.599 × 10-4, respectively and that of neat primer was 1.977 × 10-4. The corrosion protection efficiency of the primer was improved up to 7% on introduction of the PANI-based fillers. The 5 wt% of 1:1 PANI-SiG/primer composite, which contains 2.5wt% of PANI, showed better results than that of 5wt% PANI in Primer and these results are very close to that of 5wt% SiG/Primer composites.

Indoor air humidity plays a vital role in determining occupants’ health and industrial product quality. Removing excess humidity by adsorption dehumidification is still facing a challenge in finding a suitable material with high adsorption capacity and low regeneration temperature. In this study, the theoretical dehumidification capacity of prepared acorn nutshell-based activated carbons was calculated and compared with silica gel type RD and RD-2060. The calculation was based on the outdoor air condition in two Asian capital cities: Jakarta and Tokyo. The theoretical study found that prepared activated carbon has better dehumidification performance under Jakarta conditions using regeneration temperatures of less than 60°C. Under Tokyo conditions, activated carbon shows auspicious performance during the summer season. Compared with silica gels, acorn nutshell-based activated carbon has a better dehumidification capacity to process high humidity ambient air with a lower regeneration temperature.

Formaldehyde is a dangerous chemical present in many industrial waste gases. It can be recovered via catalytic processes; however, many of these require costly precious metals operating under limited reaction temperatures, making their industrialization difficult. This paper proposes a novel method of formaldehyde recovery. A sulfonation catalyst is used to promote a condensation reaction of methanol and formaldehyde to form methylal. Hence, a valuable chemical product is obtained while removing formaldehyde. A series of Al2O3-xSO3H catalysts were designed and the effects of surface acidity and hydroxyl groups on catalytic activity were explored by varying the activation temperature and sulfonation ratio. At an activation temperature of 60 °C, the yield of formaldehyde reaches 78.62% and the selectivity to methylal reaches 80.11%. This recovery rate is much higher than those reported in other studies. Through a series of characterizations, it was found that when the content of –SO3H groups is low, the hydroxyl content increases, which provides more activation centers for the formation of by-product formic acid from formaldehyde, and for the dehydration and condensation of formic acid and methanol to form methyl formate. At the same time, when the content of –SO3H groups is too high, side reactions of methanol and formaldehyde occur preferentially. Therefore, the synergistic effect of the contents of –SO3H and hydroxyl groups is the fundamental cause of the excellent catalytic performance. Based on in-situ infrared research, a possible mechanism of the reaction between methanol and formaldehyde on sulfonated silica gel is proposed, which also verifies the characterization of the catalyst. This research presents new possibilities for solving the problem of formaldehyde pollution.

The demand for dehumidification in tropical regions contributes to a significant portion of the building energy consumption. Desiccant dehumidification can mitigate energy consumption by recovering the exergy potential from the waste heat and renewable energy sources. Material development is the bottleneck in realizing the full potential of desiccant dehumidification systems beyond conventional adsorbents such as silica gel and zeolite. Therefore, it is necessary to develop novel materials that can be regenerated using the heat source under 70°C. In this study, we developed activated carbons (ACs) as the desiccant materials derived from waste biomass. The ability of activated carbon (AC) to remove the moisture was controlled by carefully preparing the material using several conditions to achieve the right operation window for optimum moisture sorption processes. The porous and surface characteristics of the newly-prepared AC were analyzed and compared with those of silica gel. The adsorption isotherm measurements were conducted, and the data were fitted with Henry-Sips and Do-Do isotherm models. The current AC exhibited an excellent water adsorption capacity (up to 0.41 g/g). The efficacy of the ACs for dehumidification applications was assessed using the weather data from several regions of Indonesia, from North Sumatera to Papua. The results revealed that under the studied conditions, the new desiccant material showed a better dehumidification capacity than silica gel. Moreover, the reported AC can be regenerated using temperatures as low as 40°C, which is readily available from waste heat, including the heat rejection from the condenser of any air-conditioning unit.

As an effective way to improve the performance of heat and mass transfer, Composite adsorbent used in adsorption refrigeration has attracted increasing research attention. The aim of the research is to reveal composite theory of silica gel composite adsorbent and to understand adsorption refrigeration system mechanism running by above composite adsorbent. Coarse porous silica gel with different particle diameters was selected as the matrix of composite adsorbent and calcium chloride was selected as additive. The results showed that composite adsorbent's thermal conductivity and adsorption capacity increased significantly compared with pure silica gel. The thermal conductivity could be increased by 58.2%, and the adsorption capacity could be increased by 4-10 times. Finally, the adsorption refrigeration system using silica gel-calcium chloride composite adsorbent was studied. A two-bed adsorption refrigeration cycle running by above composite adsorbent was adopted. The experimental results the optimal values of system cooling capacity and COP were not at the same time. The system cooling capacity reached its maximum at 1500s and the system COP reached its maximum at 1200s. The best heat recovery time was 20s. The SCP of the system was up to 288.1W kg−1, which could reduce the volume of the adsorption refrigeration system effectively.

This paper reports a laboratory study of the physical, mechanical, and thermal properties of designed composite materials based on Phenylone C1 filled with silica gel. Structural plastics, due to their high chemical and wear resistance, sufficient level of physical, mechanical, and thermal properties, can significantly improve the technical characteristics of machines and mechanisms. However, some structural plastics, including Phenylone C1, have a significant drawback – a narrow temperature range of their processing, which leads to a complication of technological equipment and increases the cost of production. It was established that the technical processing of the initial composite material into finished products could be improved by introducing fillers. The regularities of influence of silica gel content on the level of thermal and physical-mechanical properties of polymer composite materials based on Phenylone C1 have been established. It was found that the introduction of silica gel into Phenylone C1 leads to an increase in stress at the yield strength and modulus of elasticity at compression by 6.3% and 13.3%, respectively, compared to the original material. It was established that the heat resistance of the filled composite increases by 11.6% with a decrease in thermal linear expansion by 10‒20%, depending on the content of the filler. It was found that with an increase in silica gel concentration in the polymer matrix, the temperature of the onset of active destruction shifts towards higher temperatures. When filled in the amount of 30% by weight, this temperature reaches 375°C, which increases the temperature range of processing the designed material by 25°C. The study results make it possible to optimize the system of tolerances and landings of parts made of polymer-composite materials, simplify the technology of their manufacture, and, as a result, reduce their cost

Herein, a facile bottom–up approach for producing nitrogen-doped carbon quantum dots (N-CQDs) was carried out by the hydrothermal treatment of microcrystalline cellulose, in the presence of different nitrogen sources (blank/urea/ammonia water/ethanediamine(EDA)/Hexamethylenetetramine). The result showed that the fluorescence intensity and quantum yields (QYs) of N-CQDs with different nitrogen sources are all higher than that without nitrogen source. Compared with the other three nitrogen sources, N-CQDs prepared by EDA not only have the highest fluorescence intensity but also the largest QYs of 51.39%. Therefore, EDA was chosen as the nitrogen source to prepare N-CQDs. The obtained N-CQDs are uniform spherical particles with a diameter of 2.76 nm. The N-CQDs also exhibit excitation-dependent and long-wave emission properties. The emission range of N-CQDs is 470–540 nm. Moreover, N-CQDs as fluorescent agents successfully acted on purple LEDs (λem = 365 nm) to achieve white LEDs light emission. At the same time, a fluorescent thin layer chromatography plate was successfully prepared using N-CQDs, silica gel G and Sodium carboxymethylcellulose as raw materials. The separation trajectory of mixed sample of Sudan red III and kerosene on the fluorescent TLC plate is obviously clearer than that of the TLC plate.

The antidiarrhoeal effect of Waltheria indica methanol extract and fractions have been reported earlier but, the present work examined the intestinal relaxant effects of two flavonoid-phenyl propanoids isolated from the methanol extract. The active aqueous fraction was subjected to vacuum liquid chromatography using dichloromethane with increasing concentration of ethyl acetate, and that of methanol and water successively. The ten (10) fractions obtained were combined to give seven (7). The fraction 2 (C, D) was subjected to preparative thin layer chromatography on silica gel GF254 (10-40μm) using CHCl3-CH3OH (8:2) to obtain compound coded F2. Fraction 4 (F) was subjected to column chromatography using silica gel (60-120μm mesh) and eluted with dichloromethane with increasing concentrations of methanol. Fractions 9-28 were combined and subjected to column chromatography using chloroform with increasing concentration of methanol. The fractions 1-16 of these were purified on Sephadex LH-20 to obtain compound BAA. The identities of the two compounds were established using spectroscopic methods. The antidiarrheal effect of compound F2 was evaluated on mice using charcoal transit (100,200, 400mg/kg), castor oil (40, 60 mg/kg) while the two compounds were examined for their inhibitory effects on Ach-induced ileum contraction. The effects of the compounds were compared with loperamide (3mg/kg) and atropine (80μg). Compounds F2 and BAA were identified as tiliroside and 3’’’, 5’’’-dimethoxy tiliroside respectively. Tiliroside inhibited the charcoal transition in the animals in a dose dependent pattern with 400mg/ mL eliciting 63.41% inhibition compared to 59.23% produced by loperamide. The compound also elicited significantly (P

Background Modafinil (MDF) is one of the drugs used for the treatment of narcolepsy. Objective This manuscript describes the development and validation of two chromatographic stability-indicating methods for MDF in the presence of its acid-induced degradation product. Methods MDF was degraded under different stress conditions and identification of the degradation product was performed using IR and mass spectroscopy. The first method involved TLC, in which plates precoated with silica gel G60 F254 were used and the developing system was dichloromethane– methanol (9:1, v/v). The second method was an eco-friendly (HPLC) method that utilized a C-18 column and ethanol–H2O (30:70, v/v) as a mobile phase with a flow rate of 1 mL/min and UV detection at 220 nm. Results Good linear relationships were obtained within the ranges 1–10 µg/band and 2–10 µg/mL for TLC–densitometry and HPLC, respectively. The obtained results were statistically compared with those of the official HPLC method and showed no significant difference with respect to their accuracy and precision at P = 0.05. Greenness scores represent excellent green analysis results in comparison with the reported studies. Conclusions The proposed methods were validated according to ICH guidelines and were applied on bulk powder and pharmaceutical dosage forms using eco-friendly mobile phases in line with worldwide trends. Highlights Chromatographic methods have been validated for the estimation of MDF in the presence of its degradation product. Clarification of the degradation pathway and elucidation of the structure were stated for the first time. This is the first published method using greenness assessment metrics for the analysis of MDF.

A great variety of components in multivitamin preparations containing folic acid, and a variety of test methods and conditions of folic acid determination proposed by manufacturers, require alignment of test procedures for products with similar composition.The aim of the study was to compare the results of experimental verification of folic acid determination procedures which use reversed phase high-performance liquid chromatography (RP HPLC) with isocratic elution mode. Materials and methods: The Agilent 1260 Infinity II LC system with a diode array detector (280 nm), isocratic elution mode, C8- and C18-bonded silica gel chromatographic columns, model mixtures containing folic acid, cyanocobalamin, ferrous sulfate, and potassium iodide, were used in the study.Results: The lowest relative standard deviation of the folic acid peak area (RSD=0.09%), and the lowest asymmetry factor (As=1.04) for folic acid were observed for the model mixture “ferrous sulfate+folic acid+cyanocobalamin” and the following test conditions. Column: 250×4.0 mm, silica gel for chromatography, octylsilyl (C8), endcapped; mobile phase: methanol‒phosphate buffer (12:88), pH 6.6; column temperature: 25ºС. The study demonstrated the feasibility of using these conditions for determination of pteroic acid impurity with simultaneous precipitation of interfering ferrous ions, using ethylenediaminetetraacetic acid solution, pH 9.5, as a solvent.Conclusions: RP HPLC can be recommended as an optimal aligned test procedure for determination of folic acid in combination products. It is recommended to use a solution containing folic and pteroic acids for system suitability testing.

Composite materials designed by nature, such as nacre, can display unique mechanical properties and have therefore been often mimicked by scientists. In this work, we prepared composite materials mimicking the nacre structure in two steps. First, we synthesized a silica gel skeleton with a layered structure using a bottom-up approach by modifying a sol-gel synthesis. Magnetic colloids were added to the sol solution, and a rotating magnetic field was applied during the sol-gel transition. When exposed to a rotating magnetic field, magnetic colloids organize in layers parallel to the plane of rotation of the field and template the growing silica phase, resulting in a layered anisotropic silica network mimicking the nacre's inorganic phase. Heat treatment has been applied to further harden the silica monoliths. The final nacre-inspired composite is created by filling the porous structure with a monomer, leading to a soft elastomer upon polymerization. Compression tests of the platelet-structured composite show that the mechanical properties of the nacre-like composite material far exceed those of nonstructured composite materials with an identical chemical composition. Increased toughness and a nearly 10-fold increase in Young's modulus were achieved. The natural brittleness and low elastic deformation of silica monoliths could be overcome by mimicking the natural architecture of nacre. Pattern recognition obtained with a classification of machine learning algorithms was applied to achieve a better understanding of the physical and chemical parameters that have the highest impact on the mechanical properties of the monoliths. Multivariate statistical analysis was performed to show that the structural control and the heat treatment have a very strong influence on the mechanical properties of the monoliths.

A stability-indicating validated high-performance thin-layer chromatography method was performed for the determination of mometasone furoate (MM) and salicylic acid (SLY), simultaneously within the concentration range of 0.1–1.6 μg/band for MM and 0.4–5 μg/band for SLY. This method was developed to assay the investigated drugs in the presence of their degradation products by alkaline, acidic, neutral, photolytic, and oxidative degradation. Separation was achieved using dual wavelength system, 250 nm for MM and 300 nm for SLY, with mobile phase composed of chloroform–ethanol (9:1, %v/v) and stationary phase of aluminum plates pre-coated with silica gel 60 F245. The proposed method is well used for the assay and separation of MM and SLY in pure form and Elicasal® ointment. The developed method has many advantages such as being rapid, selective and inexpensive. Such advantages promote the suggested method for the high throughput assay of MM and SLY mixture, in pure form and topical preparation. The developed method was validated according to the International Council for Harmonisation guidelines, in terms of linearity, limits of detection and quantification, precision, accuracy, robustness, and specificity. Assessment of greenness has been performed depending on analytical eco-scale approach.

A family of axially chiral azepine-containing seven-membered cyclic P,N-ligands (named Indole-azepinap) have been prepared by using l-alanine as an original chirality source. The direct chromatographic separation of two diastereomeric phosphine oxides on silica gel enabled these ligands to be easy available, allowing further structural and electronic modifications. Preliminary application of these Indole-azepinaps has been demonstrated in a Pd-catalyzed asymmetric allylic alkylation with high yields and moderate enantioselectivities.

Brazilin, a constituent of the Chinese medicine heartwood, exhibits pronounced anti-tumor effects. To date, brazilin quantification mostly relies on high-performance liquid chromatography (HPLC), which is not accurate enough because of an easily oxidizable structure. Herein, a thin-layer chromatography (TLC)-based method was developed for the quantitative analysis of brazilin. A water solution of purified brazilin was spotted on a GF254 silica gel plate and developed using a mixture of chloroform‒acetone‒formic acid (8:4:1, V/V). After ammonia vaporing, AlCl3 solution (90 mg/mL) was sprayed to form a stable compound. Detection was performed at 508 nm using a dual-beam TLC scanner, and brazilin was quantitatively analyzed by using an external standard. The optimal time for ammonia vaporing was 6 min. Sample stability remained for 10‒200 min. At 508 nm, brazilin absorbance showed a good linear relationship in the range of 0‒6 μg (R2 = 0.9962). Precision RSD was no more than 3.40%, and recovery was between 100 and 105%. This novel TLC-based method has great potential for the quantitative assessment of brazilin. It is simpler, more reliable, and faster than HPLC-based analysis.

Emerging pollutants (EPs) are chemical substances that are commonly not regulated and can be detected at low or very low concentrations. However, EPs have triggered special concern because their long-term adverse effects on the environment and human health remain unknown. Most EPs show biological toxicity, environmental persistence, and bioaccumulation. Even at low concentrations in the environment, EPs may pose significant environmental and health risks. Therefore, their treatment has been explicitly included in the 14th Five Year Plan for National Economic and Social Development of the People's Republic of China and the Outline of the Long-term Goals for 2035. Soil is a source of pollutants, and its quality is directly related to economic development, ecological security, and people's livelihood. At present, China's soil environmental monitoring system is not perfect, and the ability to monitor these new organic pollutants is lagging. Therefore, to strengthen the supervision of construction and agricultural land soil environments, it is essential to strengthen the soil environment monitoring ability for these EPs and establish a reliable, steady, and economic analysis method, including their separation and analysis methods in soil. Polychlorinated naphthalenes (PCNs) have received considerable attention as emerging halogenated compounds. They were listed in Annexes A and C of the Stockholm Convention on persistent organic pollutants (POPs) in 2015 because of their persistence, multimedia fate, and toxicity. PCNs have now been detected in the surrounding soils. Owing to their trace levels in complex soil, high requirements have been put forward for the pretreatment and instrument analysis of PCNs. This study aims to develop a new method for the selective purification of PCNs in soil, which can not only effectively remove lipids and other interferences in soil but also effectively reduce time, labor, and material costs in the pre-treatment process. Based on the physicochemical properties of the 13X molecular sieve, it was explored to purify soil-extracts as solid-phase extraction (SPE) sorbents. With n-hexane as the loading and rinsing solvent, 10 mL of a dichloromethane/n-hexane mixture (2∶15, v/v) was used to elute the PCNs. Moreover, selective separation of target substances from lipid macromolecules and other interferences could be achieved simultaneously. For the selective separation of PCNs, the average recovery of the internal standard could reach 56.1% to 88.0%. 13X molecular sieves are superior to gel permeation chromatography (GPC) and Florisil SPE, and they exhibit good cleanup efficiency similar to a multilayer silica gel/alumina column (53.0%-117.0%). Although the obtained recoveries are not as high as those obtained with a multilayer silica gel/alumina column, 13X molecular sieves have advantages in terms of simple operation, environmental friendliness, and low cost. Based on these fundamental experiments, accelerated solvent extraction was used to extract targets in soil, molecular sieves were used as SPE sorbents for purification, and GC-MS/MS was employed for PCN analysis. This method was developed as a systematic analytical method for PCNs determination. The method detection limits (MDLs) for PCN homologs were in the range of 0.009-0.6 ng/g. The precision and accuracy of the method were evaluated using spiked matrices. At three spiked levels (4, 10, and 18 ng), the recoveries of PCNs (CN-3, 13, 42, 46, 52, 53, 73, and 75) were 70%-128%, 71%-115%, and 61%-114%, respectively, and the corresponding relative standard derivations were 4.2%-23%, 6.5%-31% and 4.7%-22%. Thus, this method meets the requirements of trace analysis and shows acceptable parallelism, sensitivity, accuracy, and precision, thus being feasible for the analysis of emerging pollutant. The method is expected to play an important role in sample pretreatment in the future, especially for the nationwide investigation of soil pollution.

The secondary metabolites of the phytopathogenic fungus

The catalytic activity of a base metal-terpyridine complex immobilized on silica gel (M(tpy)X2 @SiO2 /H2 O: M=Mn, Fe, Co, Ni, Cu; X=Cl, Br) for hydrosilylation was investigated. Co(tpy)Br2 @SiO2 /H2 O in the presence of NaBHEt3 exhibited the highest catalytic activity for hydrosilylation of 1-octene with diphenylsilane (Ph2 SiH2 ) to form the anti-Markovnikov-type hydrosilylation compound as the main product. The reusability of Co(tpy)Br2 @SiO2 /H2 O activated by NaBHEt3 was examined. It was found that the catalytic activity decreased with repeated use because of the peeling off of the Co complex anchor portion from the silica gel surface upon the attack of NaBHEt3 . The introduction of Co(OAc)2 instead of CoBr2 to silica gel formed Co(tpy)(OAc)2 - and Co(tpy)(OH)2 -immobilized silica gel, which exhibited catalytic activity for the hydrosilylation in the absence of an activator such as NaBHEt3 . The glassware in which Co(tpy)(OH)2 was immobilized on the inner wall was prepared. It was found that the hydrosilylation catalytically occurred on the surface of a pretreated glassware and that the catalytic activity did not decrease even after 10 repeated uses.

Aims: The present investigation is aimed at the identification and quantification of flavonoids in the methanol extract of leaves of Bauhinia acuminata Linn. (Caesalpiniaceae) by a validated HPTLC method and confirmation of the same by RP-HPLC. Methodology: CAMAG HPTLC system with VisionCATS software and HPLC Agilent Infinity 1260 were employed for the study. Pre-coated silica gel 60 F254 plates were used as stationary phase and Toluene : Ethyl acetate : Formic acid (5:4:0.2, v/v/v) was used as mobile phase in HPTLC while in HPLC Thermo hypersil BDS C18 column and Methanol and 0.4% Phosphoric acid (65 : 35) were used as stationary and mobile phase respectively. Results: Among different standards used in HPTLC, only quercetin was found to be present and further quantitatively analyzed. The method shows good correlation coefficient (R2 ≥ 0.99) and linearity in the range of 0.5 to 5.0 µg/band. The concentration of quercetin in the test extract was found to be 0.514 µg/mg of the extract. The LOD and LOQ values were 0.84 µg/band and 2.59 µg/band respectively. The RP-HPLC study also represented good % RSD of Retention time (0.025) and Area (0.09) which signifies the high precision and repeatability. The assay result (4.99 %) also indicated good presence of the quercetin in the extract. Conclusion: The methods were rapid, cost effective and may be employed for quality-control and standardization of quercetin in different plant extracts.

Scandium is one of the most valuable rare-earth elements, and its extraction is centralized in China. For this reason, the search for new scandium sources is required to supply the demand. Bauxite residue is considered a secondary scandium resource. It has estimated around 4 billion tons of bauxite residue worldwide with 20–200 mg/kg of scandium. The hydrometallurgical route is considered advantageous due to its low content. However, the acid leaching generates silica gel reducing the extraction rate and making the solid/liquid separation difficult. H2O2 can be used to avoid its synthesis, and the parameters during the leaching must be explored. Despite the studies in the literature about scandium extraction from bauxite residue, there is a lack of investigation about suppressing the synthesis of silica gel in the acid reaction. The present study aimed at the scandium extraction from bauxite residue by H2SO4 and H3PO4 leaching. The use of H2O2 was evaluated to avoid silica gel formation. The effect of time, temperature, and acid concentration was evaluated. Results showed that scandium extraction is directly related to iron extraction. The H2O2 contributed to silicon oxide formation during the acid reaction but declined scandium extraction by half. The leaching rate increased from 25 to 90 °C achieving 99% for iron and aluminum and 91% for scandium. The increase of H2SO4 concentration increased the titanium leaching. The leaching of metals using H3PO4 was similar to H2SO4 leaching. Moreover, the extractive process focused on near-zero-waste generation is essential to avoid waste stored in dams.

El estudio tuvo como objetivos la identificación y la cuantificación de colorantes sintéticos presentes en bebidas carbonatadas comercializadas en la ciudad de Trujillo. Se analizaron 9 bebidas carbonatadas y 3 refrescos instantáneos, y se usaron como patrones los colorantes Tartrazina (E102), Amarillo Ocaso FCF (E110), Rojo Allura (E129) y Azul Brillante FCF (E133) de uso comercial. Se utilizó el método de Arata-Possetto para purificar los colorantes, para la extracción de los colorantes de las bebidas y para determinar si el colorante es de naturaleza sintética. La identificación se realizó con la técnica de cromatografía en capa fina y espectrofotometría visible. Para la cromatografía en capa fina se utilizaron cromatofolios de aluminio de gel de sílice 60 y como fase móvil se utilizaron los solventes etanol, isopropanol, ciclohexano y las combinaciones isopropanol/ciclohexano; los mejores resultados se obtuvieron a una combinación de isopropanol/ciclohexano del 80 %. Se obtuvieron las longitudes de onda de máxima absorción de los colorantes patrón Tartrazina (427 nm), Amarillo Ocaso (481 nm), Rojo Allura (504 nm) y Azul Brillante (630 nm), y se logró identificar en la presencia de los colorantes analizados en las bebidas, lo cual guardó relación con lo identificado en la cromatografía. Se obtuvo la concentración de los colorantes presentes en cada una de las bebidas. Se concluye que se puede utilizar el método de Arata-Possetto, la cromatografía en capa fina y la espectrofotometría visible para identificar y cuantificar colorantes presentes en las bebidas de manera confiable los colorantes presentes en las bebidas mediante espectrofotometría visible. Se encontró además que las concentraciones de colorantes sintéticos en las bebidas están dentro de los límites establecidos por la normativa.

A TLC densitometric method was developed and validated for simultaneous determination of dutasteride and tamsulosin in their challenging combined pharmaceutical formulation, where the separation process was achieved using a mobile phase composed of ethyl acetate: methanol: hexane: ammonia (90: 5: 3: 2 by volume) on pre-coated silica gel (60 GF254) plates, densitometric quantification was performed at 270 nm for both drugs. TAMS and DUTA were resolved with Rf values of 0.57± 0.01 and 0.72 ± 0.01 with a mean percentage recovery of 100.51 ± 0.659 and 100.81 ± 0.743, respectively. Method validation was performed following the International Conference on Harmonization (ICH) guidelines and was victoriously applied for simultaneous determination of tamsulosin HCl and dutasteride in their pharmaceutical formulation. The acquired results of the Proposed method were statistically compared with those acquired by the reported methods, demonstrating no significant difference. Therefore, the proposed method has the potential for being fast, simple, economic, and selective for sustainable analysis of the cited drugs.

A novel, low-cost adsorbent material was prepared by the immobilization of humic acid on a silica gel surface coated with cross-linked chitosan (SiChiHA). The adsorbent was developed to remove selectively of Th(IV) and U(VI) from aqueous solution, including their pre-concentration and separation from lanthanides and high salinity conditions. A simple waste-less humic acid immobilization method was shown to be successful based on FT-IR, SEM-EDS, and zeta potential characterization results. The adsorbent was found to be stable over a wide pH range, with the highest capacities obtained at pH 3.5 (Th(IV)) and pH 5 (U(VI)). Langmuir model calculations yielded a maximum capacity of 30.6 mg g-1 and 75.4 mg g-1 for Th(IV) and U(VI). The adsorption process was found to be rapid (half concentration was removed within 10 min) and best described by a pseudo-second order rate equation. Increasing NaCl concentration up to 2 mol L-1 or lanthanide concentration up to 100 times did not significantly affect the removal efficiency for either Th(IV) of U(VI). Both elements could be sequentially separated by elution with ammonium citrate and nitric acid, respectively. The adsorption-desorption experiment showed that the adsorbent could be used for at least five cycles without significant capacity loss. This study provides insight into the development of low-cost adsorbent with practical functionality, including separation and regeneration ability, the advantageous properties scarcely reported in low-cost adsorbent literature.

TiO2 is supported on silica gel surface (TiO2(0.5)/SiO2(0.5) composite) by physical mixing technique of TiO2 and silica gel with mole ratio 1:1.329 TiO2(0.5)/SiO2(0.5) composite characterized by physico-chemical techniques; (SEM), (FT-IR), (DTA-TG), porosity measurements, and X-ray diffraction and used as a sorbent for 134Cs and 60Co radionuclides from aqueous solutions. Optimization of the parameters affecting sorption process is studied. The saturation sorption capacity of TiO2(0.5)/SiO2(0.5) composite towards 134Cs at pH 9.5 and 60Co at pH 5.5 are 33.1 and 17.7 m g g-1, respectively. The adsorption reaction mechanism is applicable with Freundlich isotherm and the process is spontaneous and favorable.

Background Validated ultra-performance liquid chromatography (UPLC) and thin-layer chromatography (TLC) densitometric methods were prescribed for determination of antihypertensive components. Objective To establish and validate rapid and accurate UPLC and TLC densitometric methods for determination of Xipamide and Triamterene in pure and dosage forms. Methods The first method, UPLC, depended on using an Agilent Zorbax Eclipse Plus C8 (50 mm × 2.1 mm, 1.8 μm) column, a mobile phase composed of acetonitrile-water (70 + 30, v/v) adjusted by acetic acid to obtain pH 3, 0.2 mL/min flow rate, and UV detection at 231.4 nm. The second method was a TLC densitometric method. Separation was achieved by using toluene-methanol-ethyl chloride-acetic acid (7 + 2 + 1 + 0.2, v/v/v) as the mobile phase, pre coated silica gel plates as the stationary phase, and UV detection at 300.0 nm. Results The obtained results were validated and statistically compared with official and reported methods. The obtained results showed high accuracy and reproducible results with excellent mean recoveries for both drugs. Conclusion The UPLC method showed shorter retention time for both Xipamide (0.88 min) and Triamterene (0.63 min), a lower detection limit of less than 0.055 µg/mL for both drugs with high selectivity, decreased injection volume (1 µL), and a lower flow rate than any HPLC method. Both proposed methods were sensitive, selective, and effectively applied to pure and dosage forms (Epitens®). Highlights Unprecedented sensitive, rapid, and reproducible UPLC and TLC methods were developed for selective determination of mixtures of Xipamide and Triamterene, with LOD os less than 0.076 µg/mL for both drugs.

The purpose of the current investigation is to standardize the aqueous leaf extract of Coriandrum sativum L. with a high-performance thin-layer chromatography (HPTLC) method. The method involves the determination and validation of extract with quercetin as standard. Chromatography was performed on pre-coated silica gel G 60 F254 plate as the stationary phase with formic acid, ethyl acetate and toluene as the mobile phase in the ratio 1:4:5 (V/V). Identification and quantification were conducted optical densitometrically at 254 nm. The RF value of quercetin obtained for the standard as well as the leaf extract was found to be 0.50. The method was validated for intra-day and inter-day precision and accuracy. The accuracy of the method was established by a recovery study, with 98.04 ± 0.21% average recovery of quercetin. The lyophilized coriander extract samples contained 0.058 ± 0.02% quercetin. The HPTLC method resulted in the development of an accurate, precise, reproducible and pragmatic approach to standardize the aqueous leaf extract of C. sativum L.

Rare endemic ethnomedicinal plants that are indigenous to the Piperaceae family have an ancient history as traditional medicine in the treatment of diverse ailments like gastrointestinal disorders. The present research work highlights a digitally optimized, rapid, accurate and highly sensitive high-performance thin-layer chromatography (HPTLC) method for the simultaneous screening and quantification of piperine from ex-situ cultured callus, a kind of endangered Piper trichostachyon species. Analysis of piperine was performed on thin-layer chromatography (TLC) aluminum plates pre-coated with silica gel F254 as the stationary phase. Linear ascending development was carried out in a twin-trough glass chamber with a saturation pad. Developing phase comprising of n-hexane‒ethyl acetate (5:15, V/V) was put to task. Spectrodensitometric analysis of the plate was performed in absorbance mode at 342 nm using a CAMAG TLC Scanner IV. Compact bands for piperine with RF value of 0.50 ± 0.010 were recorded exhibiting a good linear relationship with R = 99.98% in the concentration range of 100‒700 ng/spot with respect to the peak area. The proposed HPTLC method was validated in accordance with the International Council for Harmonization (ICH) guidelines for linearity, accuracy, precision, repeatability, reproducibility, limit of detection, limit of quantification, sensitivity, and specificity. The total piperine content was found to be 62.39 μg/mL in the wild plant and 41.57 μg/mL in the callus of P. trichostachyon. The chromatographic analysis concluded that the method developed and validated as a novel effort for the concurrent evaluation and comparative quantification of piperine in species of P. trichostachyon is reproducible and selective for the analysis of piperine.

Qualitative and quantitative analyses of quercetin (Qu) and isorhamnetin (Is) in Hippophae rhamnoides L. fruits hydrolysis products from 10 different origins were conducted by high-performance thin-layer chromatography (HPTLC), using 3% sodium acetate silica gel G plate (Anhui Liangchen), dichloromethane–ethyl acetate–formic acid (7:3:1, V/V) as the developing reagent, 1% ethanol solution of aluminum trichloride as the chromogenic agent, scanning at a wavelength of 390 nm. The content of Qu and Is in H. rhamnoides L. fruits hydrolysis products from 10 different producing areas was determined. The results showed that the RF value of Qu was 0.48 ± 0.05, the linear range was 0.06–0.42 μg/μL, and the correlation coefficient was 0.9990, indicating that the linear correlation of Qu was good. The RF value of Is was 0.64 ± 0.05, the linear range was 0.04–0.44 μg/μL, and the correlation coefficient was 0.9993, indicating that the linear correlation of Is was good. The precision analyses of Qu and Is showed that the RSD was

A precise, accurate and sensitive high-performance thin-layer chromatographic method has been developed and validated for the simultaneous determination of montelukast and bilastine in a tablet dosage form which is used in the treatment of allergic rhinitis. The proposed method used aluminum plates pre-coated with silica gel 60F254 as the stationary phase and acetonitrile–ethyl acetate–ammonia (4:6:0.1, V/V) as the mobile phase for separation purpose. Densitometric detection was carried out at 282 nm in ultraviolet. Compact spots of montelukast and bilastine were obtained at RF 0.53 and 0.27, respectively. Linear responses were shown by the detector over the range of 100‒500 ng/band for montelukast and 200‒1000 ng/band for bilastine. The proposed method was validated as per the International Council for Harmonisation guidelines. The method was applied for the estimation of both drugs in tablet formulation and their synthetic mixture.

The purpose of this study was to evaluate the influence of the chemical polishing, when compared to the mechanical polish, in the sorption, solubility and microhardness of a heat-polymerizable acrylic resin. The heatactivated acrylic resin used was Clássico (Art. Odontológicos Clássico Ltda., S.P.). The properties of sorption and the solubility were tested in accordance with International Organization for Standartization (ISO) specification n. 1567, making 20 samples in the format of disks, divided aleatory in two groups, where the first group received lhe mechanical polish with abrasive pastes, and the second, the chemical polish during IOS, in the chemical polisher PQ 9000 (série 4868-2, Termotron do Brasil Ltda., Piracicaba, SP). The samples were maintained in a desiccator with silica gel, at 37 DC, until the moment they reached constant mass (M1), obtained in a scale with resolution of 0,0001g. The samples were submerged in distilled water, at 37 Uc, for 7 days, when it was Obtained new mass value (M2). The difference between M1 and M2 divided by the volume Of each sample resulted in the sorption. The samples were desiccated again until they reach constant mass (M3). The difference between M1 and M3 divided by the volume of each sample resulted in the solubility Of the same ones. For the Knoop microhardness measurement, were made 20 specimens of acrylic resin, of which 10 samples received the mechanical polish and the others, the chemical polish. The Knoop microhardness test was made with a NU Research Microscope (VEB Carl Zeiss JENAGermany). The results indicated that the technique of the chemical polish is acceptable when considered the sorption property, even so unviable with the solubility property, in accordance with the specification n.1567 of ISO. The chemical polish also reduced significantly the superficial microhardness of the acrylic resin, which consequences can interfere in the clinical performance of the material.

Penelitian ini bertujuan untuk mengisolasi dan mengidentifikasi senyawa golongan alkaloid dari beberapa sampel tumbuhan yang dipakai. Metode studi literatur review ini berasal dari tinjauan pustaka dan studi lainnya dengan mengumpulkan berbagai literatur yang relevan. Senyawa alkaloid merupakan senyawa organik terbanyak ditemukan di alam. Hampir seluruh alkaloid berasal dari tumbuhan dan tersebar luas dalam berbagai jenis tumbuhan. Pemeriksaan pada tanaman yang mengandung alkaloid terdapat beberapa tahapan, yaitu pengeringan, ekstraksi, fraksinasi, dan isolasi. Isolasi senyawa alkaloid dapat dilakukan dengan menggunakan beberapa metode. Dalam proses ekstraksi digunakan metode maserasi 3x24 jam, selanjutnya proses fraksinasi menggunakan Kromatografi Cair Vakum (KCV) dengan fase diam silika gel dan fase gerak n-heksan: etil asetat dan fraksi tersebut diisolasi lagi menggunakan Kromatografi Kolom Gravitasi (KKG) dengan fase diam silika gel dan fase gerak nheksan: etil asetat. Fraksi tersebut dianalisis kemurniannya menggunakan Kromatografi Lapis Tipis (KLT) dengan fase diam silika gel254.

Aim: Nicotine Substituted 1,3,4 Oxadiazole and pyrazole moieties were integrated by utilizing hydrazide as halfway .Oxadiazole were acquired by two techniques one is by utilizing PoCl3 within the sight of fragrant corrosive ,other is by utilizing carbon disulphide in the presence ofpotassium hydroxide as an impetus .Pyrazoles were likewise gotten by ehtylacetoacetate we acquired unrefined item and again it was recrystallized by utilizing alcohol.All incorporated mixtures were evaluated for Antibacterial activity and enaminones showed promising action against standard medication ciprofloxacin. Methods: TLC on silica gel G was used to check for homogeneity of the title compound. H NMR, Mass, and IR Spectra were used to characterise these compounds, and their antibacterial activity was tested. Results: All of these compounds, including nicotine substituted ester, hydrazide, 1,3,4 Oxadiazole, and pyrazole, showed antibacterial activity. The maximum activity of enaminones was comparable to that of the standard drug ciprofloxacin (5mcg). Compound1 showed potent antimicrobial activity Conclusion: In the zone of inhibition studies, all six samples at MIC concentrations showed reasonable antimicrobial activity Compound1 showed very good antimicrobial activity

An increase in temperature of up to 2 °C occurs when the amount of CO2 reaches a range of 450 ppm. The permanent use of mineral oil is closely related to CO2 emissions. Maintaining the sustainability of fossil fuels and eliminating and reducing CO2 emissions is possible through carbon capture and storage (CCS) processes. One of the best ways to maintain CCS is hydrate-based gas separation. Selected type T1-5 (0.01 mol % sodium dodecyl sulphate (SDS) + 5.60 mol % tetrahydrofuran (THF), with the help of this silica gel promotion was strongly stimulated. A pressure of 36.5 bar of CO2 is needed in H2O to investigate the CO2 hydrate formation. Therefore, ethylene glycol monoethyl ether (EGME at 0.10 mol %) along with SDS (0.01 mol %) labeled as T1A-2 was used as an alternative to THF at the comparable working parameters in which CO2 uptake of 5.45 mmol of CO2/g of H2O was obtained. Additionally, it was found that with an increase in tetra-n-butyl ammonium bromide (TBAB) supplementation of CO2, the hydrate and operating capacity of the process increased. When the bed height was reduced from 3 cm to 2 cm with 0.1 mol % TBAB and 0.01% SDS (labelled as T3-2) in fixed bed reactor (FBR), the outcomes demonstrated a slight expansion in gas supply to 1.54 mmol of CO2/g of H2O at working states of 283 K and 70 bar. The gas selectivity experiment by using the high-pressure volume analysis through hydrate formation was performed in which the highest CO2 uptake for the employment of silica contacts with water in fuel gas mixture was observed in the non-IGCC conditions. Thus, two types of reactor configurations are being proposed for changing the process from batch to continuous with the employment of macroporous silica contacts with new consolidated promoters to improve the formation of CO2 hydrate in the IGCC conditions. Later, much work should be possible on this with an assortment of promoters and specific performance parameters. It was reported in previous work that the repeatability of equilibrium moisture content and gas uptake attained for the sample prepared by the highest rates of stirring was the greatest with the CIs of ±0.34 wt % and ±0.19 mmol of CO2/g of H2O respectively. This was due to the amount of water occluded inside silica gel pores was not an issue or in other words, vigorous stirring increased the spreadability. The variation of pore size to improve the process can be considered for future work.