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Exploring tazarotene, a third-generation retinoid for potential hand osteoarthritis treatment, this study presents the development and validation of an ultra-performance liquid chromatography with quadrupole detector mass spectrometry (UPLC-QDa) method for the simultaneous quantification of tazarotene and tazarotenic acid, its active metabolite, in porcine skin. Method development involved a design-of-experiments approach for chromatographic optimization of gradient steepness, organic solvent volume, column temperature, capillary voltage, flow rate, and cone voltage. Central composite orthogonal design was used to optimize peak area, peak width, retention time, and resolution. Validation was performed in accordance with U.S. Food and Drug Administration guidelines. The method was linear over the concentration range of 0.4–18,750 ng/mL for tazarotene and 13.3–12,500 ng/mL for tazarotenic acid, with r2 values of ≥0.99. Chromatographic analysis demonstrated acceptable accuracy and precision (<15%), and stability tests confirmed the analytes' stability under various conditions. This validated method offers a reliable and accurate approach for the simultaneous analysis of tazarotene and tazarotenic acid, facilitating further research into their therapeutic applications for hand osteoarthritis. [ABSTRACT FROM AUTHOR]

Vitamin K consumption needs to be monitored in people taking warfarin since it can impact the anticoagulation response. Vegetables are the primary nutritional source of Vitamin K1, in the form of Vitamin K1. The aim of this study was to measure the level of Vitamin K1 in various vegetables that were commercially sold in three major Bandung markets and were ingested by patients using warfarin at Hasan Sadikin Central General Hospital Bandung. High-performance liquid chromatography with an ultraviolet detector set at 245 nm was the analytical technique. One hundred percent methanol was used as the mobile phase, and it was isocratically eluted at a flow rate of 0.6 mL/min with a T3 column maintained at 25°C. The results indicated that the following Vitamin K1 levels were found in lettuce: 38.4391 ± 15.2650–64.4419 ± 19.0315 µg/100 g, in napa cabbage: 56.7445 ± 0.1569–273.2828 ± 8.3061 µg/100 g, in cabbage: 27.9531 ± 1.7487–217.0457 ± 7.2201 µg/100 g, and in spinach: 305.2868 ± 3.3058–970.7098 ± 14.1167 µg/100 g. The highest Vitamin K1 level was in spinach and the lowest was in lettuce. [ABSTRACT FROM AUTHOR]

A sensitive determination procedure was presented for two anticancer drugs (tamoxifen and raloxifene) in real water and biological samples based on magnetic dispersive micro solid-phase extraction–high-performance liquid chromatography with an ultraviolet detector. Fe3O4 NPs@SiO2@TiO2 nanocomposite was synthesised as a magnetic sorbent by the sol-gel technique. The effective parameters in the procedure were optimised with an experimental design, including screening and optimisation steps. Under the optimum determination conditions, the procedure displayed wide linear ranges of 5.3–735.0 and 7.0–806.0 ng mL−1 with R-squared of 0.9916 and 0.9908, limit of detections of 1.6 and 2.1 ng mL−1 for the raloxifene and tamoxifen determination, respectively. The intra-day relative standard deviations were 3.76 and 3.59% for three times the raloxifene and tamoxifen measurements, respectively. The preconcentration factors for the raloxifene and tamoxifen determination with a concentration of 20 ng mL−1 were 506.1 and 546.7, respectively. The method was applied to analyse well water, tap water, and hair samples and determine raloxifene and tamoxifen simultaneously with recoveries between 88.5–96.4 and relative standard deviations lower than 8.4%. The method's advantages for raloxifene and tamoxifen measurement included easy operation, low sorbent and desorption solvent consumption, simple sorbent preparation and separation, and suitable analysis time. [ABSTRACT FROM AUTHOR]

A large amount of atmospheric emissions result from various anthropogenic activities worldwide. Given the complexity of volatile organic compounds (VOCs) and their different adsorption capacities, redox potentials, and photolytic properties, an air purification system for the removal of VOCs that combines multiple physical processes was proposed in this study using toluene as an example. These processes include, in the first step, an adsorption treatment (AT) with activated carbon (AC), where toluene adsorption results from the insertion of aromatic rings (nonpolar groups) between the graphitic carbon planes, as demonstrated by the Raman spectroscopy; in the second step, electrochemical treatment (ECT) using TiO2,nt|Ti||SS‐304 electrodes applying an electric field to accelerate the oxidation of toluene through the production of free radicals (⋅OH), hydroperoxyl radicals and benzyl groups, followed by the rupture of aromatic rings to generate aliphatic compounds and the consequent mineralization to CO, CO2, and H2O; in the third step, photolytic treatment (PT) with a 254‐nm UV lamp for toluene degradation is used, which is influenced by the addition of radicals, such as ⋅OH or ⋅O−2ad, to transform toluene into either benzene or phenol. The multistep system integrating AT, ECT and PT was more efficient overall (99.58 %) than the individual treatments (AT=50.29 %, ECT=44.38 %, and PT=52.71 %) as evaluated by gas chromatography with a BID detector; it showed enhanced efficiency enabled by the synergistic effects of combining multiple technologies to enhance the overall toluene degradation efficiency and flexibility. The multistage systems can be adapted to specific contamination conditions and process requirements with the generation of residual toluene, phenol, and aliphatic compounds and possible mineralization to molecules such as CO2, CO, and H2O. This small and portable multistep system provides a novel approach for treating outdoor and/or indoor air contaminated with toluene. [ABSTRACT FROM AUTHOR]

Polyether antibiotics (PAs) are the anti-coccidiosis drugs used for treating and preventing coccidiosis. Studies show the residues of these antibiotics in food cause adversities and threaten human health. PAs thus need robust, rugged, and accurate methods for their analysis. This review encompasses pretreatment and detection methods of PAs in diverse matrices since 2010. Both conventional and developed methods are part of the pretreatments, such as dispersive liquid-liquid microextraction, solid-phase extraction, solid-phase microextraction, solvent front position extraction, QuEChERS (Quick Easy Cheap Effective Rugged and Safe), supercritical fluid extraction, and others. The analysis methods involve liquid chromatography coupled with detectors, sensors, etc. The pros and cons of various techniques for PAs have been discussed and future tendencies are proposed. HIGHLIGHTS: Progress of pretreatment and analytical methods for PAs are summarized. Comparisons between different mass analyzers are discussed in detail. Novel materials in microextraction methods are depicted. [ABSTRACT FROM AUTHOR]

This study aimed to investigate antibiotic residues such as oxytetracycline, ciprofloxacin, enrofloxacin and levofloxacin, in both pasteurised and raw cow's milk. A method using high-performance liquid chromatography with a UV detector (HPLC-UV) was developed and validated following International Conference on Harmonization (ICH) guidelines for simultaneous detection and quantification of these residues. The technique demonstrated linearity, with r2 values ranging from 0.999 to 1.00 within the 1.3–15.0 μg ml−1 range for each antibiotic. Thirty cow's milk samples, raw and pasteurised, from Dhaka's local markets were analysed, revealing the presence of enrofloxacin and levofloxacin, while oxytetracycline was absent in all samples. Notably, pasteurised milk samples contained enrofloxacin, levofloxacin and oxytetracycline, with groups P6 and P7 exceeding the Maximum Residue Limit for enrofloxacin, levofloxacin and ciprofloxacin (121 µg l−1). This study emphasises antibiotic residues in milk, with a validated method holding promise for routine analysis in industries requiring simultaneous quantitation of multiple antibiotics. [ABSTRACT FROM AUTHOR]

In this work, the covalent organic frameworks–incorporated electrospun nanofiber membranes were used as a highly efficient adsorbent to enrich quinolone antibiotics in food samples. Covalent organic frameworks composed of 1,3,5‐tris(4‐aminophenyl) benzene and 2,5‐dihydroxyterephthalaldehyde were rapid prepared only 20 min at room temperature, then were further synthesized into electrospun polyacrylonitrile nanofiber membranes by electrospinning the binary precursors solution directly. Coupled with high‐performance liquid chromatography with ultraviolet detector, the method exhibited good linearity in the range of 1–100 ng·mL−1 for four quinolone antibiotics, with low limits of detection 0.19–0.34 ng·mL−1 (signal‐to‐noise ratio = 3). The recoveries of four quinolone antibiotics were 86%–116%, and relative standard deviations of the intra‐ and interday for four quinolone antibiotics were 0.7%–9.0%, respectively. The practical application of the thin film microextraction method using nanofiber membranes as adsorbent for detecting four quinolone antibiotics in animal‐derived food samples was demonstrated. [ABSTRACT FROM AUTHOR]

The fall armyworm, Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae) is a devastating invasive pest recently introduced in India in 2018. The fall armyworm infestation has significantly impacted maize cultivation in the country. Identifying the host plant volatiles (kairomones) that are attractive to S. frugiperda from its highly preferred host plant, i.e. maize will help developing eco-friendly management strategies against this nefarious pest. Gas chromatography electroantennogram detector (GC-EAD) analysis revealed that a total of 18 compounds in maize headspace volatiles and 17 in maize leaf extract elicited an antennal response in female moths of S. frugiperda. Olfactometer bioassays of GC-EAD active plant volatile compounds revealed that heptanoic acid, 2,5-ditert butyl-1,4-benzoquinone and n-hexadecane were the most preferred plant volatile compounds and 50: 50 ratio blend of heptanoic acid and 2,5-ditert butyl-1,4-benzoquinone was found to be the most attractive kairomone blend for S. frugiperda. [ABSTRACT FROM AUTHOR]

This study aimed to assess the presence of ochratoxin A (OTA) residues in the blood serum of slaughtered pigs in Greece. Samples were obtained from 1695 healthy slaughtered pigs originating from 113 different farms located in 21 geographic regional units in 8 different geographic regions of Greece and were analyzed using an immunosorbent assay (ELISA) and high-performance liquid chromatography with fluorescence detector (HPLC-FD). OTA contamination assessment showed that 782 (46.1%) and 1233 (72.7%) samples were OTA-positive, with a concentration range of 0.20–5.38 μg/L and 0.15–5.96 µg/L according to ELISA and HPLC-FD analysis, respectively. Also, 88 (77.9%) and 108 (95.6%) of farms were found to be OTA-positive by ELISA and HPLC-FD analysis, respectively. The highest OTA serum positivity rate (>98%) and toxin level (5.96 µg/L) determined by HPLC-FD were observed in the Thessaly region, whereas a high prevalence of up to 100% (range 75–100%) was found on farms in the Crete Island region. The detection of OTA in the serum of slaughtered pigs in different regions in Greece poses a risk for animal and human health and highlights the need for constant OTA monitoring in the swine industry and pork meat production facilities. [ABSTRACT FROM AUTHOR]

Ochratoxin A (OTA), which is one of the most important mycotoxins in terms of human health, can be found in cereal products such as bread, "bazlama" (traditional flatbread), and pita bread, as well as cereals such as wheat, barley, and corn. This study aimed to determine the effect of different fermentation times, baking, and storage for various periods on the presence of OTA in sourdough bazlama. Bazlama flour was contaminated with OTA concentrations of 5 and 10 μg/kg. After two different fermentation times (1.5 and 3 h), baking at 300 ± 5°C, and storage at room temperature (25 ± 2°C) for 0, 5, and 10 days, the change in OTA levels of bazlama samples was determined by the high‐performance liquid chromatography with fluorescence detector (HPLC‐FLD) method. The effect of different storage periods on the presence of OTA is insignificant. Although a general decrease in OTA level has been determined, it has been found that long‐term fermentation (at least 3 h) was more effective, especially in flours with a high concentration (10 μg/kg) of OTA contamination. It has been determined that bazlama made from contaminated flours with OTA levels of 5 and 10 μg/kg contained OTA levels exceeding 3 μg/kg when long‐term fermentation was not used. This is the maximum permitted limit set by the Turkish Food Codex and the European Commission, indicating that it is not suitable for consumption in this position. [ABSTRACT FROM AUTHOR]

The synthesis of pentoxifylline contained three different kinds of genotoxic contaminants. While 6-chloro-2-hexanone is possibly genotoxic, 3,7-dimethyl-1-(5-oxohexyl)-2,3,6,7-tetrahydro-1H-purine-2,6-dione is not; structural alert for genotoxic mutagenicity and carcinogenicity is present. According to the structural alert and QSTR model consensus, 1-bromo-3-chloropropane and 3-chloro-1-propanol are both genotoxic. For most volatile and semi-volatile analytes, gas chromatography (GC) with direct liquid injection and a flame ionization detector (FID) is the appropriate method. The suggested approach was shown to be very effective, precise, linear, accurate, and specific in monitoring three genotoxic contaminants. Pharmaceutical examination of 6-chloro-2-hexanone, 1-bromo-3-chloropropane, and 3-chloro-1-propanol. GC techniques were used to analyze these contaminants. The method is particularly sensitive to quantifying 6-chloro-2-hexanone, 1-bromo-3-chloropropane, and 3-chloro-1-propanol contaminants at 0.3 ppm and 0.9 ppm, respectively, according to the results of the LOQ and LOD methods. The goal of this work is to determine threshold amounts and appropriate methodologies for quantifying the three genotoxic contaminants that may be present during pentoxifylline production. [ABSTRACT FROM AUTHOR]

This study investigated the sorption and residues of phosphine in fruits and vegetables relevant for export. Sorption patterns varied among the commodities: mango exhibited a constant sorption range of 10–12%, bitter gourd displayed a distinct pattern with peak sorption of 20% at 8 hours, and chilli demonstrated a higher range of sorption percentage, peaking at 60% at 8 hours. ANOVA (F (4,8) = 0.449, p = 0.771) and regression (F (1,11) = 0.851, p = 0.376) analysis revealed a non-significant relationship between the sorption percentage and exposure period. Residue analysis using Gas Chromatography with FPD detector revealed relatively low levels of phosphine residues in mango (0.009–0.01 µL/L), negligible traces in chilli samples, residues within the maximum residue limit (MRL) range for bitter gourd after 4–6 hours of aeration. Detecting phosphine residues within acceptable limits underscores the significance of post-fumigation protocols to meet stringent food safety standards, thereby safeguarding product integrity for global trade. Therefore, phosphine fumigation could serve as a viable alternative to methyl bromide fumigation for quarantine treatment of perishables as it doesn’t leave detectable toxic residues in produce following aeration and has no role in ozone depletion thus making it a more sustainable solution for international trade in fresh produce. [ABSTRACT FROM AUTHOR]

A method based on high-performance liquid chromatography with a UV detector (HPLC-UV) was developed for the simultaneous determination of sorbic acid, benzoic acid, and natamycin in yogurt. The method does not require time-consuming, labor-intensive pre-treatment processes or complicated procedures. Using a C18 150 mm × 4.6 mm, 3.0 µm column (Roc) at 25°C, the target analytes were separated within 5 minutes with high sensitivity and selectivity. The mobile phase consisted of trifluoroacetic acid (0.1%) in water containing 100 mM sodium acetate, trifluoroacetic acid (0.1%) in acetonitrile, and trifluoroacetic acid (0.1%) in tetrahydrofuran, in a ratio of 70:20:10 (v/v). Using this mobile phase as an extraction mixture, recoveries ranged from 83.0% to 110.2% at spike levels between 2.5 µg/kg and 80.0 µg/kg. The relative standard deviations (RSDs) for these recoveries were below 10%. Intra-day precision and inter-day precision varied from 5.3% to 6.7% and 7.6% to 9.2%, respectively. Additionally, the limits of detection (LOD) were between 0.24 and 0.61 mg/L, and the limits of quantification (LOQ) ranged from 0.80 to 2.0 mg/L for sorbic acid, benzoic acid, and natamycin. Principal component analysis revealed that yogurt type had the greatest positive influence on preservative concentration, while the weight or volume of the yogurt package had the greatest negative influence. [ABSTRACT FROM AUTHOR]

Simple Summary: Menbutone is a drug that increases hepato-digestive secretions and has been used for more than 50 years in Europe to treat a wide number of digestive disorders in livestock and dogs. However, despite this use, little is known about its pharmacokinetics, more specifically in cattle. This work contributes to a better knowledge of the pharmacokinetics of menbutone when administered intravenously and intramuscularly to cattle (12 Holstein calves), being the first study to describe it in this animal species. After intravenous administration, the drug showed a moderate volume of distribution and a fast elimination from the body. After intramuscular administration, menbutone exhibited quick and high absorption. Menbutone is a choleretic agent currently used in Europe to treat digestive disorders in livestock and dogs. Pharmacokinetic parameters were established in 4-month Holstein calves after intravenous (IV) and intramuscular (IM) administration. The drug was administered to 12 animals (10 mg/kg) for both IV and IM routes following a crossover design. Plasma samples were collected at various time points over 24 h and analyzed by reverse-phase high-performance liquid chromatography with a photodiode-array detector, following a method validated according to European Medicines Agency guidelines. Pharmacokinetic parameters were calculated using compartmental and non-compartmental methods. Menbutone followed a two-compartment open model after IV injection, with a total clearance (Cl) of 71.9 ± 13.5 mL/h/kg, an elimination half-life (t½β) of 4.53 ± 2.45 h, and a volume of distribution at steady-state (Vss) of 310.4 ± 106.4 mL/kg. Non-compartmental elimination half-life (t½λ) was 4.2 ± 1.1 h. After IM administration, drug pharmacokinetics was best described by a one-compartment open model. The peak plasma concentration (Cmax) was 15.1 ± 4.3 µg/mL; the time to reach Cmax (tmax), 1.66 ± 0.55 h; and the mean absorption time (MAT), 2.50 ± 1.42 h. Absorption was high, with a fraction of the dose absorbed (F) of 83.5 ± 22.4%. Menbutone was rapidly eliminated from plasma for both routes of administration, with a fast and high IM bioavailability. [ABSTRACT FROM AUTHOR]

Summary: The present study investigated the volatile and sensory profiles and antioxidant activity of 1,8‐cineole type Niaouli essential oil from Madagascar for which limited information is reported in literature. The volatile compounds were identified by Gas chromatography–mass spectrometry and semi‐quantitative results were obtained by Gas chromatography with a flame‐ionisation detector; the odour descriptors were determined by a trained panel using a Quantitative Descriptive Analysis. The antioxidant activity was determined, too. Several volatiles, most of these here firstly, have been identified; 1,8‐cineole (eucalyptus‐like) prevailed, followed by viridiflorol and (E)‐nerolidol. 'Eucalyptus‐like, fresh‐mint, woody, sweet‐floral and spicy' odour descriptors have been defined. Volatiles resulted in agreement with the odour descriptors. The data allowed to characterise the Niaouli essential oil; considering its volatile composition, pleasant sensory notes and antioxidant activity the 1,8‐cineole type Niaouli essential oil from Madagascar could be considered a promising flavouring agent and natural preservative in the food industry. [ABSTRACT FROM AUTHOR]

In this study, a magnetic porous polymer composite with both hydrophilic and hydrophobic groups was synthesized for magnetic solid phase extraction (MSPE) of milk substrates. Optimization was conducted on various parameters, including adsorption dose, solution pH, adsorption time, and some elution conditions. Coupled with a high-performance liquid chromatography fluorescence detector, a novel MSPE method for determination of norfloxacin (NFX), ciprofloxacin (CIP), and enrofloxacin (ENR) in milk was developed based on magnetic metal organic framework polystyrene polymer (Fe3O4@MOF@PLS) as adsorbent. The Fe3O4@MOF@PLS exhibited significantly improved adsorption performance compared to MOF and PLS. Under optimized experimental conditions, the method exhibited good linearity for the three fluoroquinolones (FQs) in the range of 0.5–1000 μg/kg, with limit of detections (LODs) ranging from 0.21 to 1.33 μg/kg, and limit of quantitations (LOQs) from 0.71 to 4.42 μg/kg. The relative standard deviation (RSD) for the three FQs were 3.4–8.8%. The recoveries of three FQs in milk samples ranged from 84.2% to 106.2%. This method was successfully applied to the detection of three FQs in 20 types of milk, demonstrating its simplicity, speed, and effectiveness in analyte enrichment and separation. The method presented advantages in adsorbent dosage, adsorption time, LODs, and LOQs, making it valuable for the analysis and detection of FQs in milk. [ABSTRACT FROM AUTHOR]

This study investigates the impact of changing parameters on the photocatalytic degradation of carbofuran (CBF) using laser-treated TiO2 nanotube arrays on a Ti mesh under simulated sunlight irradiation and assessing toxicity during photocatalytic degradation. Various parameters, including the stirring effect, light intensity, initial CBF concentration, and variation in the active surface area of laser-treated TiO2 photocatalysts, were examined to determine their impact on degradation efficiency. The photodegradation kinetics were monitored using ultra-performance liquid chromatography with a PDA detector (UPLC-PDA) and UV-Vis spectrophotometry, while mineralization was assessed by a total organic carbon (TOC) analyzer. The photocatalytic degradation of CBF is enhanced by an increase in the active surface area of the TiO2 photocatalyst, light intensity, and the introduction of stirring, but it decreases with an increase in the initial concentration of CBF. The toxicity assessments revealed that the cytotoxicity of CBF initially increased during the degradation process but decreased after further treatment, indicating the formation and subsequent breakdown of toxic intermediates. The phytotoxicity test showed that longer degradation times resulted in higher toxicity to plant growth. This study provides new insights into the photocatalytic degradation of CBF with TiO2, the importance of parameter optimization for more efficient treatment, and the use of toxicity tests to confirm the success of the photocatalytic process. [ABSTRACT FROM AUTHOR]

Traditional Chinese medicine (TCM) has garnered significant scientific interest in healthcare but faces increased regulatory scrutiny due to concerns about uncontrolled usage. This study focuses on characterizing Pogostemon cablin (PC) to mitigate potential misuse and identify chemotype differences. Leveraging untargeted metabolomics, we identified 222 distinctive features effectively differentiating PC from Agastache rugosa (AR), reducing misidentification risks. Pogostone and tilianin emerged as potential markers, leading to a high‐performance liquid chromatography‐diode array detection (HPLC‐DAD) method development for PC and AR discrimination. Evaluation of PC chromatograms revealed notable profile and pogostone level differences among samples, suggesting chemotype associations. Untargeted metabolic profiling identified 78 features with significant differences, highlighting 7,3′,4′‐tri‐O‐methyleriodictyol as a potential discriminatory marker between PC chemotypes. The developed HPLC‐DAD method quantified pogostone and 7,3′,4′‐tri‐O‐methyleriodictyol, effectively discriminating PC chemotypes. This platform differentiates PC and AR and distinguishes chemical types within PC, like pogostone‐type and patchoulol‐type. Applied to local TCM stores, it ensures PC authenticity. This approach addresses TCM control concerns, enhancing understanding and application of herbal medicine by providing insights into PC chemical composition and discrimination. [ABSTRACT FROM AUTHOR]

The salting-out assisted liquid–liquid extraction (SALLE) method with the liquid chromatography ultraviolet-visible detector (LC-UV) has been developed and validated for the simultaneous determination of seven antibiotic compounds of five different therapeutic classes (β-lactams), amoxycillin, ampicillin, penicillin G, (sulphonamides), sulfamethoxazole, (aminoglycosides) gentamicin, (fluoroquinolones) ciprofloxacin and (macrolide) erythromycin, in the cow milk samples. The LC conditions for separation of the selected antibiotic compounds were achieved with the reversed phase isocratic elution. The mobile phase consisted of 0.05 M Na2HPO4, acetonitrile and methanol (70:10:20 v/v/v). The mobile-phase flow rate was 1 mL min−1 with the injection volume of 20 μL and all the seven standard compounds were eluted within 14 min. The developed analytical method has been validated for the linearity, precision, sensitivity, accuracy, specificity, decision limit (CCα), and detection capability (CCβ). Experimental parameters influencing the extraction efficiency were evaluated and optimised. Under the optimum experimental conditions, good linearity over wide concentration ranges was obtained with the coefficient of determination R2 > 0.9989 for all the antibiotics. The limits of detection (LODs) and quantification (LOQs) ranged from 1.28 to 2.46 µg mL−1 and 3.87–7.46 µg mL−1, respectively. The relative standard deviations for the repeated analysis were below 8% indicating acceptable method precision. The accuracy study yielded satisfactory recoveries in the ranges 95.5–103% for the pure standard compounds and 83.8–112% for the spiked matrix-match milk samples. The results of the study revealed that the developed method is simple and fast and the SALLE method is appropriate for the simultaneous determination of targeted five multiclass antibiotic residues in the cow milk samples by LC-UV/Vis with a better efficiency. [ABSTRACT FROM AUTHOR]

Aims The present work aimed to distinguish the indigenous Aspergillus flavus isolates obtained from the first (pioneer) grain corn farms in Terengganu, Malaysia, into aflatoxigenic and non-aflatoxigenic by molecular and aflatoxigenicity analyses, and determine the antagonistic capability of the non-aflatoxigenic isolates against aflatoxigenic counterparts and their aflatoxin production in vitro. Methods and results Seven A. flavus isolates previously obtained from the farms were characterized molecularly and chemically. All isolates were examined for the presence of seven aflatoxin biosynthesis genes, and their aflatoxigenicity was confirmed using high performance liquid chromatography with fluorescence detector. Phylogenetic relationships of all isolates were tested using ITS and β-tubulin genes. Of the seven isolates, two were non-aflatoxigenic, while the remaining were aflatoxigenic based on the presence of all aflatoxin biosynthesis genes tested and the productions of aflatoxins B1 and B2. All isolates were also confirmed as A. flavus following phylogenetic analysis. The indigenous non-aflatoxigenic isolates were further examined for their antagonistic potential against aflatoxigenic isolates on 3% grain corn agar. Both non-aflatoxigenic isolates significantly reduced AFB1 production of the aflatoxigenic isolates. Conclusion The indigenous non-aflatoxigenic A. flavus strains identified in the present work were effective in controlling the aflatoxin production by the aflatoxigenic A. flavus isolates in vitro and can be utilized for in situ testing. [ABSTRACT FROM AUTHOR]

Analysis of melatonin in biological samples is a challenge for the analyst both because of its low concentration and because of the numerous interfering substances. Therefore, chromatography, as a powerful analytical technique used for the separation, detection, and quantification of analytes, can be the method of choice for determining melatonin in biological samples for clinical use and pharmacokinetic research. The method was developed and validated according to the internal documents in accordance with Good Laboratory Practice. The concentrations of melatonin in human serum were determined using a high-performance liquid chromatography method with a fluorescence detector and mirtazapine as an internal standard. Preparation of serum samples was performed by liquid–liquid extraction with ethyl acetate: n-hexane (1:1 v/v). High linearity was exhibited over a concentration range of 25–10,000 pg/mL of melatonin, with a correlation coefficient higher than 0.999 during the course of method validation. Repeatability and intermediate precision show a relative standard deviation lower than 6.6 %, and accuracies were from 90.7 % to 110.3 %. The lower limit of quantitation was 30 pg/mL, and the limit of detection was 7.92 pg/mL. The in-house method is simple, fast, reproducible, and applicable for the determination of melatonin in human serum. [ABSTRACT FROM AUTHOR]

Synsepalum dulcificum (Miracle fruit) is a tropical plant in West and Central Africa, which has been historically used for treating diarrhea in humans and animals. Pharmacological research has shown that the leaves of the plant possess anti-hyperlipidemia activity. However, its anti-hyperlipidemic components have not been reported. In this study, the leaves of S. dulcificum were extracted using 95% ethanol and the extract was fractionated using different polar solvents. The anti-hyperlipidemia activity of the extract and fractions were evaluated using the zebrafish model. The results showed that the ethyl acetate (EA) fraction displayed the best anti-hyperlipidemic effect. A comparison of the high-performance liquid chromatography equipped with diode array detector (HPLC-DAD) profiles of the ethanol extract and different fractions at 350 nm indicated that a peak at 37.4 min has the highest intensity in the EA part, relatively. Then the chemical constituents of the extract and the active fraction were extensively identified using UPLC-Q-Exactive-Orbitrap-MS/MS, showing the main peak was quercitrin and other components in the EA part mainly included quercitrin analogs. Furthermore, the quercitrin was isolated from the plant and its contents in the extract and fractions were determined using high-performance liquid chromatography with ultraviolet detector (HPLC-UV) method. The quantitative results showed that the content of quercitrin in the EA fraction was 10.04% (w/w). Further pharmacological study indicated that quercitrin also possessed potent anti-hyperlipidemia activity (improvement rates of liver fat and total cholesterol were 75.6% and 92.5% at 40 μg/mL, respectively). Besides, quercitrin showed little toxicity to zebrafish embryos. [ABSTRACT FROM AUTHOR]

In order to establish a simple method for detecting acrylamide in food, this article optimizes the determination conditions, sample and processing conditions using highperformance liquid chromatography ultraviolet detector. The research results show that, the samples defatted by hexane, ultrasonic extraction in chloroform. The analytes were isolated by reversed phase high performance liquid chromatography on a C18(4.6x250mm, 5μm) column and eluted with 5% methanol aqueous solution at a flow rate of 0.8mL/min. The detection wavelength was 210 nm, Quantitative analysis method was external standard method. The experimental results indicated that the linearity of the calibration curve was good in the range of 0.2μg/ml~2.5μg/ml (r=0.9991), and the recoveries of acrylamide from spiked samples by this method were within 87.6%~97.8% (n=5). The method was simple, accurate, reliable and suitable for the determination of acrylamide in potato chips, instant noodles, biscuits, bread and other starchy foods. Compared with traditional methods, this method does not rely on expensive Mass spectrometry detection equipment and is easily adopted by most laboratories, which is conducive to its promotion and application in the food testing industry. [ABSTRACT FROM AUTHOR]

In the current study, chromatographic and in silico techniques were applied to investigate the biotransformation of ethyl 5-(4-bromophenyl)-1-(2-(2-(2-hydroxybenzylidene) hydrazinyl)-2-oxoethyl)-2-methyl-1H-pyrrole-3-carboxylate (11b) in hepatocytic media. The initial chromatographic procedure was based on the employment of the conventional octadecyl stationary phase method for estimation of the chemical stability. Subsequently, a novel and rapid chromatographic approach based on a phenyl–hexyl column was developed, aiming to separate the possible metabolites. Both methods were performed on a Dionex 3000 ThermoScientific (ACM 2, Sofia, Bulgaria) device equipped with a diode array detector set up at 272 and 279 nm for analytes detection. An acetonitrile: phosphate buffer of pH 3.5: methanol (17:30:53 v/v/v) was eluted isocratically as a mobile phase with a 1 mL/min flow rate. A preliminary purification from the biological media was achieved by protein precipitation with methanol. A validation procedure was carried out, where the method was found to correspond to all ICH (Q2) and M10 set criteria. Additionally, an in silico-based approach with the online server BioTransformer 3.0 was applied in an attempt to predict the possible metabolites of the title compound 11b. It was hypothesized that four CYP450 isoforms (1A2, 2C9, 3A4, and 2C8) were involved in the phase I metabolism, resulting in the formation of 12 metabolites. Moreover, docking studies were conducted to evaluate the formation of stable complexes between 11b and the aforementioned isoforms. The obtained data indicated three metabolites as the most probable products, two of which (M9_11b and M10_11b) were synthesized by a classical approach for verification. Finally, liquid chromatography with a mass detector was implemented for comprehensive and summarized analysis, and the obtained results revealed that the metabolism of the 11b proceeds possibly with the formation of glucuronide and glycine conjugate of M11_11b. [ABSTRACT FROM AUTHOR]

The content and composition of volatile aroma compounds in strawberries of the Ducat, Honey and Polka varieties were studied using GCMS analysis. To identify volatile compounds, an Agilent Technologies 6890 chromatograph with a 5973 mass spectrometric detector and a DB-5 chromatographic capillary column (inside diameter 0.25 mm and length 30 m) was used. Esters (12.8–41.8%), aldehydes (5.9–15.9%), ketones (8.7– 35.6%), furanones (22.7–24.4%), organic acids (2.47–21.85%), aroma compounds, lactones, terpenic compounds and alkanes were identified in the aroma. It was found that the aroma of strawberries of the Polka variety is presented by ethyl butanoate (30.7%), 2,5-dimethyl-4-methoxy-3(2H)- furanone (mesifurane) (19.9%), trans-2-hexenal (15.6%), acetoin (8.7%) and 2,5-dimethyl-4-hydroxy-3(2H)-furanone (3.7%). Ducat berries contain – acetoin (35.7%), 2,5-dimethyl-4-methoxy-3(2H)-furanone (mesifurane) (19.8%), trans-2-hexenal (11.3%), ethyl butanoate (10.1%) and 2,5- dimethyl-4-hydroxy -3(2H)-furanone (4.4%). The main aroma compounds of Honey berries are 2,5-dimethyl-4-methoxy-3(2H)-furanone (mesifurane) (19.1%), ethyl butanoate (14.1 %), hexanoic (caproic) acid (9.5%), acetoin (8.2 %), trans-2-hexenal (5.3 %), hexadecanoic acid (5.1%), 2,5-dimethyl-4- hydroxy-3(2H)-furanone (3.4%). In terms of aroma activity in berries, 2,5- dimethyl-4-methoxy-3(2H)-furanone (mesifurane) and 2,5-dimethyl-4- hydroxy-3(2H)-furanone (furaneol) prevail, with slightly lower activity of ethyl 2-methylbutanoate, ethyl butanoate and trans-2-hexenal. It has been proven that the aroma of strawberries grown in the Right-Bank ForestSteppe of Ukraine is most characterised by sweet, caramel tones, while fruit and green tones are less pronounced. [ABSTRACT FROM AUTHOR]

Copyright of Biomédica: Revista del Instituto Nacional de Salud is the property of Instituto Nacional de Salud of Colombia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Sulfur hexafluoride (SF6), which survives in the atmosphere for an extremely long period of time, is the most potent greenhouse gas regulated under the Kyoto Protocol. So, the accurate monitoring of atmospheric SF6 plays an important role in the study of the control policies for reducing greenhouse gas emissions. The instruments for SF6 measurement are typically calibrated using certified reference materials. The concentrations of the commercially available SF6 reference materials usually have a broad range, from 1 μmol/mol to 6000 μmol/mol. Some characteristics including sensitivity, linear range, relative standard deviation, and accuracy are crucial for the determination of SF6 in such a broad concentration range. Therefore, the selection of a proper detector for the accurate determination of SF6 with such a broad range is extremely important to establish a gas chromatography (GC) method for developing SF6 reference materials. In this paper, several typical GC methods with different detectors, including a thermal conductivity detector (TCD), a pulsed discharge helium ionization detector (PDHID), and a flame photometric detector (FPD), were carefully established for the accurate determination of SF6 with different concentrations. The results show that an FPD detector has a relatively narrow linearity range, thus a quadratic equation should be established for building a calibration curve. The PDHID and TCD have good linearity with coefficients of 1.0000 in the concentration range of 10–100 μmol/mol (using a PDHID), and 100–1000 μmol/mol (using a TCD), respectively. Further considering the measurement errors of indication results, the PDHID is suitable for SF6 measurement when the concentrations are below 100 μmol/mol, whereas the TCD is suitable for SF6 measurement when the concentrations are over 100 μmol/mol. These results provide useful guidance in choosing an appropriate GC detector for the accurate determination of SF6, which are especially very helpful for developing SF6 reference materials. [ABSTRACT FROM AUTHOR]

This review highlights the advantages of high-precision liquid chromatography with an electrochemical detector (HPLC-ECD) in detecting and quantifying biological samples obtained through intracerebral microdialysis, specifically the serotonergic and dopaminergic systems: Serotonin (5-HT), 5-hydroxyindolacetic acid (5-HIAA), 3,4-dihydroxyphenylacetic acid (DOPAC), dopamine (DA), 3-metoxytryptamin (3-MT) and homovanillic acid (HVA). Recognized for its speed and selectivity, HPLC enables direct analysis of intracerebral microdialysis samples without complex derivatization. Various chromatographic methods, including reverse phase (RP), are explored for neurotransmitters (NTs) and metabolites separation. Electrochemical detector (ECD), particularly with glassy carbon (GC) electrodes, is emphasized for its simplicity and sensitivity, aimed at enhancing reproducibility through optimization strategies such as modified electrode materials. This paper underscores the determination of limits of detection (LOD) and quantification (LOQ) and the linear range (L.R.) showcasing the potential for real-time monitoring of compounds concentrations. A non-exhaustive compilation of literature values for LOD, LOQ, and L.R. from recent publications is included. [ABSTRACT FROM AUTHOR]

Using 6-aminoquinolyl- N -hydroxysuccinimidyl carbamate as a pre-column derivatization reagent, optimized derivatization and chromatography parameters, a simple high-performance liquid chromatography fluorescence detector (HPLC–FLD) method was developed and validated to determine 23 related amines in plasma and cortex of C57BL/6 mice with cerebral ischemia–reperfusion injury. The prepared samples were separated on a ZORBAX SB-C18 column (4.6 mm × 250 mm, 5 μm) with 60% acetonitrile (ACN) and 20 mM sodium acetate solution (pH adjusted to 5.0 by phosphoric acid). All analytes achieved good separation within 1.2 h at a flow rate of 1 mL/min. The limits of detection and limits of detection quantitation of the method were ranged from (0.1–9.2) to (0.3–30.6) ng/mL, respectively. The analytical method was apt for simultaneously determining 23 amino acids in plasma and cortex. Our results revealed that the relevant amino acids were significantly altered (P  < 0.05) in C57BL/6 mice. [ABSTRACT FROM AUTHOR]

Gas chromatography (GC) is a versatile analytical technique widely employed for the determination of various compounds, including sulfur hexafluoride (SF6). SF6 is a potent greenhouse gas and its accurate measurement is crucial for environmental monitoring and industrial applications. Different detectors in GC offer varying sensitivity, selectivity, and detection limits, affecting the precision and accuracy of SF6 quantification. This article provides a comprehensive evaluation of different GC detectors for the precise determination of SF6, highlighting their advantages, limitations, and applicability. [ABSTRACT FROM AUTHOR]

In this research, an eco-friendly method was established by vortex-assisted dispersive liquid-liquid microextraction based on the deep eutectic solvent (VA–DLLME–DES). The performance of the proposed method was demonstrated by the determination of benzene, toluene, ethylbenzene, and xylene (BTEX) in blood samples of fuel stations workers combined with GC–FID. The selected hydrophilic deep eutectic solvent is consisting of l-menthol and (1S)-(+)-camphor-10-sulfonic acid (CSA) at a 5:1 molar ratio as a green solvent instead of traditional toxic organic solvents. Under the optimal extraction conditions, the introduced method exhibited good linearity with a coefficient of determinations (r2) higher than 0.9985 and an acceptable linear range of 0.03–80 µg l–1. Accordingly, the limits of detection (S/N = 3) and limits of quantification (S/N = 10) were in the ranges of 0.01–0.04 µg l−1 and 0.03–0.10 µg l−1, respectively. Blood BTEX levels of fuel stations workers were analyzed based on age, duration of working at the station, smokers or nonsmokers, and station type (CNG, gasoline, and dual-purpose). The results showed that there was no significant difference between blood BTEX levels in different age groups, while the concentration of BTEX compounds increases with the increase of working time in the station. Blood BTEX levels were much higher in smokers than in nonsmokers. [ABSTRACT FROM AUTHOR]

In this work, a sensitive analytical method based on packed-nanofiber solid-phase extraction (PFSPE), after derivatization with trichloroacetic acid and high-performance liquid chromatography with a fluorescence detector (HPLC-FLD), has been established for the determination of aflatoxins (AFs) in milk. Polystyrene polymeric multi-walled carbon nanotube (PS-MWCNT/OH) composite nanofibers were fabricated by electrospinning and used to prepare homemade extraction columns. The extraction efficiency of the HPLC-FLD analysis method was sufficiently investigated and validated. After the implementation of optimal conditions, all of the analytes were separated efficiently and the components of the milk matrix did not disturb the determination. The obtained linear ranges of the calibration curves were 0.2–20 ng/mL for AFTB1 and AFTG2, 0.1–10 ng/mL for AFTB2, and 0.4–40 ng/mL for AFTG1. The recoveries ranged between 80.22% and 96.21%. The relative standard deviations (RSDs) for the intra-day and inter-day results ranged from 2.81–6.43% to 3.42–7.75%, respectively. Generally, 11 mg of sorbent and 200 μL of elution solvent were used to directly extract all of the AFs from the milk matrix. Reported herein is the first utilization of PS-MWCNT/OH-PFSPE HPLC-FLD to simultaneously analyze the occurrence of aflatoxins in milk. [ABSTRACT FROM AUTHOR]

Detectors in gas chromatography (GC) are unique in all analytical science. The detector performs several difficult functions that make sensitive and selective analysis possible. In this instalment, we will explore the challenges involved in detecting the effluent from a capillary gas chromatographic column, and summarize the many detector options. We will then consider basic ideas and tasks that allow detectors to function properly. Finally, we will examine some specific troubleshooting and preventative maintenance tips for common detectors. We will see that, with some simple preventative thinking and action, detectors in gas chromatography can provide excellent sensitivity and selectivity for years of use. [ABSTRACT FROM AUTHOR]

Gas Chromatography (GC) is a versatile analytical technique widely employed for the determination of various compounds, including Sulfur Hexafluoride (SF6). SF6 is a potent greenhouse gas and its accurate measurement is crucial for environmental monitoring and industrial applications. Different detectors in GC offer varying sensitivity, selectivity and detection limits, affecting the precision and accuracy of SF6 quantification. This article provides a comprehensive evaluation of different GC detectors for the precise determination of SF6, highlighting their advantages, limitations and applicability. [ABSTRACT FROM AUTHOR]

The mastic tree, scientifically known as Pistacia lentiscus, which belongs to the Anacardiaceae family, was used in this study. The aim of this research was to analyze the chemical composition of this plant and assess its antioxidant and antibacterial properties using both laboratory experiments and computer simulations through molecular docking, a method that predicts the binding strength of a small molecule to a protein. The soxhlet method (SE) was employed to extract substances from the leaves of P. lentiscus found in the eastern region of Morocco. Hexane and methanol were the solvents used for the extraction process. The n-hexane extract was subjected to gas chromatography-mass spectrometry (GC/MS) to identify its fatty acid content. The methanolic extract underwent high-performance liquid chromatography with a diode-array detector (HPLC-DAD) to determine the presence of phenolic compounds. Antioxidant activity was assessed using the DPPH spectrophotometric test. The findings revealed that the main components in the n-hexane extract were linoleic acid (40.97 ± 0.33%), oleic acid (23.69 ± 0.12%), and palmitic acid (22.83 ± 0.10%). Catechin (37.05 ± 0.15%) was identified as the predominant compound in the methanolic extract through HPLC analysis. The methanolic extract exhibited significant DPPH radical scavenging, with an IC50 value of 0.26 ± 0.14 mg/mL. The antibacterial activity was tested against Staphylococcus aureus, Listeria innocua, and Escherichia coli, while the antifungal activity was evaluated against Geotrichum candidum and Rhodotorula glutinis. The P. lentiscus extract demonstrated notable antimicrobial effects. Additionally, apart from molecular docking, other important factors, such as drug similarity, drug metabolism and distribution within the body, potential adverse effects, and impact on bodily systems, were considered for the substances derived from P. lentiscus. Scientific algorithms, such as Prediction of Activity Spectra for Substances (PASS), Absorption, Distribution, Metabolism, Excretion (ADME), and Pro-Tox II, were utilized for this assessment. The results obtained from this research support the traditional medicinal usage of P. lentiscus and suggest its potential for drug development. [ABSTRACT FROM AUTHOR]

Background: Factors associated with interindividual variability in the pharmacokinetics of micafungin have been identified. This variability can cause underexposure and loss of drug efficacy. For this reason, a simple, fast, cost-effective and sensitive ultra-performance liquid chromatography ultraviolet detector (UPLC-UV) method was developed and validated for the quantification of micafungin. Methods: The method involves simple plasma precipitation by UPLC with a reversed phase C18 column at 40°C coupled with ultraviolet detection set at a wavelength of 264 nm. The mobile phase consisted of a mixture 42/58 of potassium phosphate 20 mm and acetonitrile. Results: The method was validated over the concentration range of 0.25–15.0 mg/L and proved to be reliable and reproducible with an average percentage of recoveries of 101.59 ± 3.93% and inter and intraday variation coefficients lower than 15% in all cases. The method was successfully applied in determining 30 samples from 10 patients being treated with micafungin. Conclusions: The method proposed could be useful to facilitate the implementation of therapeutic drug monitoring for personalizing micafungin treatment in invasive fungal infections. [ABSTRACT FROM AUTHOR]

BACKGROUND: As the main source of iodine intake, water is of practical significance to detect the content of iodide accurately. At present, the common methods for the analysis of iodide in water samples include ion chromatography, gas chromatography, colorimetry, spectrophotometry. The analysis results of different methods can be affected by the actual sample matrix and experimental conditions. Our project team organized 38 laboratories to determine the content of iodide in natural water samples by ion chromatography, starch spectrophotometry, catalytic reduction spectrophotometry, and inductively coupled plasma-mass spectrometry (ICP-MS), the results showed that there were significant differences among the measured values by different methods, and the data were obviously dispersed. OBJECTIVES: To discuss the reasons for the differences between the results of different methods and give suggestions on the selection of iodide analysis methods under different conditions, based on the principles and conditions of each method. METHODS: Four analysis methods, including ion chromatography, starch spectrophotometry, catalytic reduction spectrophotometry, and ICP-MS, were used to determine the content of iodide of the groundwater sample by 38 laboratories. High performance liquid chromatography-inductively coupled plasma-mass spectrometry (HPLC-ICP)MS) was used to determine the content of iodide by our own laboratory. RESULTS: (1) HPLC-ICP-MS can be used to effectively separate iodide and iodate ions in water samples. Through the quality control of the experimental process by blank samples, standard reference materials and replicate samples, the analytical results of this method were accurate and reliable. The determination results of iodide in JSH-2 samples were 78.32μg/L. 　　(2) The determination values of iodide by ion chromatography (83.38μg/L) were consistent with those by HPLC-ICP-MS (78.32μg/L). However, the data of ion chromatography between different laboratories were obviously dispersed. The determination values of iodide by the starch spectrophotometry (92.95μg/L), catalytic reduction spectrophotometry (101.84μg/L) and ICP-MS (103.13μg/L) were higher than those by HPLC-ICP-MS. 　　(3) The reasons for the differences between the results of different methods were discussed, based on the principles and conditions of each method: 　 　① The determination results of ion chromatography may be affected by the selection of experimental conditions, such as sample pretreatment, chromatographic column and detector, and other interfering components. 　 　② It is not considered whether there is iodate ion in the sample itself in the starch spectrophotometry. Therefore, when there are iodate ions in the water sample, the determination result is actually the total content of inorganic iodine. 　　③ The standard working curve of the catalytic reduction spectrophotometry is bent downward as a whole and does not show a good linear relationship. Therefore, when the response value of iodide is high, the concentration value will be high. 　　④ ICP-MS is only used to determine the total content of elements, and cannot be used for elemental speciation analysis. There are iodate ions in the samples of this experiment, so the determination results of ICP-MS should be the total content of iodine, rather than the content of iodide. CONCLUSIONS: When iodate ions are present in water samples, starch spectrophotometry and ICP-MS may lead to a high result of iodide determination. Among them, starch spectrophotometry is usually suitable for samples with an iodide concentration of 25-500μg/L, and ICP-MS can be combined with other separation techniques to improve method selectivity. When iodate ions are present in water samples, catalytic reduction spectrophotometry and ion chromatography can be used to analyze the concentration of iodide, but the influence of sample concentration level, matrix interference components, experimental conditions and other factors should be considered. HPLC-ICP-MS can be applied to the quantitative analysis of iodine species in water samples, which can avoid the influence of iodate ions on the accuracy of iodide determination results. [ABSTRACT FROM AUTHOR]

The barrier discharge ionization detector (BID) is one of the latest detection technologies used in gas chromatography (GC). 306 papers from 2012 to 2021 with GC-BID analyses were considered. An overview of the main applications with the BID, considering the trends for the most common analyses, explored compounds, extraction methods, and comparative studies with other detectors is shown. Interest in BID applications has grown, and the number of publications reflects this. Despite having the potential to analyze different compounds, gases are more explored, mainly H2, CH4, and CO. The BID should be further explored for water analysis, as studies show its good performance in larger quantities and at the level of traces. Most of the determinations of these compounds were applied in studies focused on CO2 reduction (by photocatalysis or electro-reduction) and biogas (for CH4). BID is effective for determinations on the order of mmol to µmol. Headspace extraction (HS) is most often applied BID analysis. Reduced dynamic range and nonlinear response to carbon mass are some disadvantages to BID. On the other hand, the BID has a signal-to-noise ratio (S/N) 100 times higher than thermal conductivity detector (TCD) (for inorganic gases and water), a high linear sensitivity for dodecane (LOD less than 1.0 pgC/sec) and other compounds (being able to reach µg/L). Combined with simple extraction methods such as HS, the BID allows quick and simple analysis with great sensitivity, in addition, it is a good alternative for the analysis of inorganic gases and water compared to usual detectors. [ABSTRACT FROM AUTHOR]

Tenvermectin (TVM) is a novel 16‐membered macrolide compound isolated and purified from the fermentation broth of genetically engineered Streptomyces avermitilis strain MHJ1011. TVM and ivermectin were administered at the dose of 0.3 mg/kg body weight through a single subcutaneous injection route followed by plasma collectiom and analysis at different time intervals. Plasma concentrations of TVM and IVM were determined by high‐performance liquid chromatography with fluorescence detector. Pharmacokinetic analysis was completed using the non‐compartmental method with WinNonlin™ 6.4 software. TVM is rapidly absorbed after administration with peak plasma concentrations (Cmax, 9.78 ± 2.34 ng/ml) obtained within 6–22 h. AUC0‐last was 586.86 h·ng/ml ± 121.24 h·ng/ml. The mean elimination half‐life of TVM (T1/2λz) was 97.99 h ± 46.41 h. The T1/2λz of IVM was 146.59 h ± 22.26 h in the study. The present study showed that subcutaneous administration of TVM at 0.3 mg/kg body weight (BW) in swine is absorbed more rapidly than IVM in swine. Compared to the pharmacokinetic characteristics of IVM, there was little difference in the half‐life of TVM among different individuals. The data will contribute to refining the formulation and dosage regime for TVM administration. [ABSTRACT FROM AUTHOR]

Fountain pen ink contains dyes, pigments, or nanoparticles as colorants; water and ethylene glycol or an organic solvent as the vehicle. The dyes in fountain pen ink are usually negatively charged acid dyes. In this study, various types of black fountain pen ink (5 dye‐based and 5 nanoparticle‐based) were investigated by ultraviolet–visible (UV–Vis) absorption spectroscopy, Ion Pair High Performance Liquid Chromatography Diode‐Array Detector (IP‐HPLC‐DAD), Matrix Assisted Laser Desorption/Ionization Time‐of‐Flight Mass Spectrometry (MALDI‐TOF‐MS), and Liquid Chromatography Quadrupole Time‐of‐Flight Mass Spectrometry (LC‐Q/TOF‐MS) analysis. UV–Vis spectroscopy of fountain pen ink samples showed different profiles despite their similar color. MALDI‐TOF‐MS analyses successfully differentiated 10 of the inks. Nanoparticle‐based ink, which is usually darker than dye‐based ink, showed the same UV absorption at 240 nm. The use of LC‐Q/TOF‐MS, however, allowed the 5 dye‐based fountain pen ink samples to be differentiated from one another. On the basis of the combined results of all analytical methods mentioned above, the discriminating power values were 0.71–1.00. Among them, MALDI‐TOF‐MS could successfully distinguish fountain pen ink samples with similar black colors and provide an easy analytical approach for the differentiation and identification of various types of fountain pens. [ABSTRACT FROM AUTHOR]

Copyright of Plant & Soil Science is the property of National University of Life & Environmental Sciences of Ukraine and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This study evaluates the formation of 13 polycyclic aromatic hydrocarbons (PAHs) in chicken thighs and breasts, cooked by different methods. These methods are: madhbi, charcoal mandi, electric oven mandi, gas flame oven mandi and shawaya. Chicken samples were collected from a restaurant in Riyadh, Saudi Arabia. Analysis of the samples was carried out using high-performance liquid chromatography with a fluorescence detector (HPLC-FLD). The data obtained showed that madhbi chicken had higher PAHs levels than other cooking styles, with the mean concentration in chicken breast of 87.72 µg/kg and thigh of 75.56 µg/kg. Phenanthrene was the compound detected at the highest concentration in different cooking methods. There was no significant difference in concentration of PAHs between the parts of chicken cooked with the same method. However, the method of cooking had a significant impact on the formation of PHAs. Therefore, the formation of PAHs in chicken meat could be reduced by choosing appropriate cooking methods. Moreover, the margin of exposure was used to assess the health risk in adults due to madhbi chicken ingestion. The results showed that there is no serious health concern [ABSTRACT FROM AUTHOR]

A novel chemiluminescence detector for high-performance liquid chromatography (HPLC) was designed that incorporates a smartphone as photodetector, signal processor, and data storage unit. All detector components, including flow cell, flow cell holder, mixers, and housing, were fabricated by 3D printing and integration of the smartphone and 3D printed components provides a portable, low-cost, and user-friendly device. The detector was applied in the determination of carbamazepine using HPLC through a chemiluminescence reaction with tris(2,2′-bipyridyl)ruthenium(II) and cerium sulfate. Design and fabrication of the flow cell using two fabrication methods—3D printing and laser cutting—along with the integration of a mixer and the optimization of smartphone parameters were investigated. To expand the applicability of the detector for other analytes and different chemiluminescence reactions, detection of three piperazine derivatives by reaction with tris(2,2′-bipyridyl)ruthenium(II) and four phenethylamine compounds via reaction with acidic potassium permanganate reagent was studied. The linear dynamic range, limit of detection, and limit of quantification of the detector for the determination of carbamazepine were measured as 3.0–30.0 mg/L, 1.0 mg/L, and 3.0 mg/L, respectively, using the Samsung S20 smartphone device. Intraday and interday precision was evaluated for carbamazepine, with relative standard deviation (RSD) values for intraday precision ranging from 1.7 % to 6.2 % (n = 3) and interday precision RSD values ranging from 3.2 % to 4.8 % (n = 9). [Display omitted] • Smartphone-based chemiluminescence detection is integrated with HPLC. • 3D printed flow cells were designed to increase customizability and reduce cost. • MATLAB was applied for image processing and chromatogram generation. • Carbamazepine was quantified using the smartphone-based detector. [ABSTRACT FROM AUTHOR]

The effective differentiation and detection of multiple tea polyphenols are often challenging due to their subtle structural similarities. Although post-column derivatization HPLC strategies are commonly employed to distinguish multiple targets, the short physical distance between chromatographic column and detector limits reaction time, thereby reducing the derivatization efficiency. Dopamine (DA) reacts rapidly with resorcinol to form fluorescent azamonardine products, making fast fluorometric derivatization of tea polyphenols containing resorcinol motifs possible. In this study, a DA-driven rapid and post-column fluorescence derivatization method has been applied to sensitively detect eight tea polyphenols. This method is based on fluorescence derivatization and possesses low background interference, high sensitivity, and excellent reproducibility. Moreover, the practical application of this proposed fluorometric derivatization platform was further validated by simultaneous identification of multiple tea polyphenols in different tea samples. This work has great potential to become an alternative to the National Standard method for tea polyphenols determination. [Display omitted] • Dopamine can act as novel fluorescence derivatization agent for tea polyphenols. • The retention time of tea polyphenols is extended after derivatization. • Eight tea polyphenols are distinguished using post-column derivatization HPLC. • The analysis of tea polyphenols contents in different tea samples is realized. [ABSTRACT FROM AUTHOR]

This study presents a gas chromatographic detector using alternating current (AC) discharged in air to generate μ-arc at atmosphereic pressure. This air-based μ-arc emission detector (μ-AED) was assembled by two stainless-steel syringe needles inside a quartz tube. The length of μ-arc (i.e., distance of discharge) measures 550 μm. The organic compounds with various functional groups were chromatographically separated and fed into the μ-AED. The intensity changes in the emission spectrum were recorded as these compounds passing through the μ-arc. When organic compounds pass through the μ-arc, the changes in emission intensity could go either increase or decrease depending on the input power and underlying mechanisms. It was found that when operating the μ-arc at relatively low power, organic samples present as negative peaks, and better S/N ratio were obtained. The detection limits (3σ/s) range from 209 pg for n -butyl acetate to 552 pg for 1-chloropentane. A selectivity study reveals that μ-AED is more sensitive to oxygen-containing and aromatic compounds. The μ-AED developed in this study demonstrates the simplest design with reasonable miniaturization. The direct discharge in air makes this μ-AED suitable for future application with μ-GC which uses scrubbed air as carrier gas and eliminates bulky gas cylinders. [Display omitted] • A novel gas chromatographic μ-arc emission detector working under air carrier gas. • The μ-arc emission detector demonstrates good linearity and a sub-nanogram detection limit. • Functional groups related sensitivity changes for organic molecules are discovered. [ABSTRACT FROM AUTHOR]

A method was developed for the simultaneous determination and analysis of sildenafil, vardenafil, and tadalafil in honey-mixed herbal sachets using high-performance liquid chromatography with a UV detector (HPLC–UV). This method eliminates the employment of complex procedures and abolishes time-consuming and labour-intensive pre-treatment processes. In ten minutes, the separation process (at 25oC) of sildenafil, vardenafil, and tadalafil using a C18 150 mm × 4.6 mm x 5 μm column (Shim-pack GIST) was successful with high selectivity and sensitivity. The mobile phase was a 60:40 (v/v) mixture of 0.1 percent formic acid in water and 0.1 percent formic acid in acetonitrile. Using the mobile phase as an extraction mixture, it gave recoveries in the range of 93.0-103.3% at spike levels of 50–150 mg/kg with relative standard deviations (RSDs) lower than 10%. The intra-day and interday precision results were in the range of 0.4–0.8% and 1.0–1.7%. Furthermore, the retention times for sildenafil acid, vardenafil acid, and tadalafil were 1.93, 2.47, and 9.62 minutes, respectively, and the limits of detection (LOD) were 1.70, 2.16, and 1.03 mg/L, while the limits of quantification (LOQ) were 5.65, 7.21, and 3.42 mg/L. [ABSTRACT FROM AUTHOR]

The aim of this study from 2020 was to identify the role of rivers, including those with low water flow and a constant inflow of bisphenol A (BPA), 4-tert-octylphenol (4-t-OP) and 4-nonylphenol (4-NP) to the marine environment. Water samples were collected from the small rivers flowing into the Gulf of Gdańsk and from the Vistula River. Final assays were performed using high-performance liquid chromatography with a fluorescence detector (HPLC-FL). The highest concentrations of phenol derivatives were found in summer, most likely due to higher consumption of products containing phenol derivatives. Another factor may be the type of development in the catchment area. The measurements did not exceed the PNEC, though this does not mean that the amounts of phenol derivatives introduced into the Gulf of Gdańsk by rivers can be ignored. Mean loads of xenobiotics introduced to the sea via rivers have been calculated as over 320 kg y−1 of BPA and about 55 kg y−1 of 4-t-OP and 4-NP each. [ABSTRACT FROM AUTHOR]

New data on the fatty acid compositions of the muscle tissues of the two most widespread families of the mesopelagic zone—the Myctophidae (Notoscopelus kroyeri and Symbolophorus veranyi) and Stomiidae (Chauliodus sloani, Stomias boa, Borostomias antarcticus, and Malacosteus niger) families—were obtained from the Irminger Sea (North East Atlantic). The fatty acids (FAs) in the total lipids (TLs), phospholipids (PLs), triacylglycerols (TAGs), and cholesterol esters and waxes were analyzed using gas–liquid chromatography with a mass-selective detector and flame-ionized detector (GC-MS and GC-FID, respectively). Species-specific differences in the FA/alcohol profiles of the studied fishes were revealed. A directed deep-vise trend in the changes in the content and performance of certain FAs for the studied species was found. Along with this, a general character of dominance for monounsaturated fatty acids (MUFAs), which were discussed as food tracers, was revealed. MUFAs in the muscle tissues included dietary markers of zooplankton (copepods)—20:1(n-9) and 22:1(n-11), the content of which varied in association with the species—such that the biomarker Calanus glacialis predominated in muscles of B. antarcticus and C. hyperboreus prevailed in other studied species. Different strategies of compensatory adaptation to depth gradient in lipid metabolism among the studied species were discussed. [ABSTRACT FROM AUTHOR]

Pyrodinium bahamense var compressum is a harmful dinoflagellate that produces saxitoxin, which causes paralytic shellfish poisoning (PSP) that is deadly to humans. A non-axenic culture of P. bahamense was established using f/2 media from samples collected from Sepanggar Bay, Kota Kinabalu, Sabah. Toxin analyses of cultures harvested on days 60, 120, 180, and 360 were performed using high-performance liquid chromatography with a fluorescence detector and compared with samples collected at the same location during the bloom in 2021. The highest cell toxin content was found in the bloom sample (86.2 fmole/ cell), and no toxin was detected in the culture 60 days old. In addition, cell toxin content for the P. bahamense culture was low (9.4-16.5 fmole/cell). Based on the toxin profile, P. bahamense comprises 84-98% of gonyautoxin 4. In summary, the current findings add to the existing knowledge of the toxin profiling of P. bahamense, a toxic, harmful algal bloom species, thus, leading to better toxin management. [ABSTRACT FROM AUTHOR]

This study evaluated the bioavailability of polycyclic aromatic hydrocarbons (PAHs) in Santos Bay (SB) and the adjacent Santos Continental Shelf (SCS) in Brazil. Biliary metabolites were measured in several fish species to establish a baseline for future monitoring programs. Bile samples from different species of fish were collected monthly from July to December 2005 in SB, and in August 2005 and February 2006 on SCS. Metabolite concentrations were determined using high-performance liquid chromatography with fluorescence detectors. Naphthalene, phenanthrene, and benzo[a]pyrene metabolite concentrations ranged from 24 to 810 µg g-1 of bile, 1.8 to 68 µg g-1 of bile, and below the limit of quantitation to 1.3 µg g-1 of bile, respectively. Despite its high concentrations, the levels of naphthalene metabolites were in regions of low-contamination, while benzo[a]pyrene metabolite were in the same range as those reported in moderately contaminated areas, which may indicate pyrolytic contamination by PAHs. No significant differences in the metabolite concentrations were found between the SB and the SCS samples or during the periods of collection. Future studies with a single biomonitoring species should be conducted, considering age, sex, and feeding condition of the individuals. The metabolite data presented in this study is an important baseline information for this urbanized region, which hosts several sources of contaminants. [ABSTRACT FROM AUTHOR]