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Abstract Precise, fast, and reliable identification and quantification of microplastic contamination are essential for determining their environmental concentrations for risk assessments. This study investigates the use of nuclear magnetic resonance (NMR) spectroscopy to quantify microplastics by analysing dilution series of polystyrene (PS), polyisoprene-cis (PI), polybutadiene-cis (PB), polylactic acid (PLA), polyvinyl chloride (PVC) and polyurethane (PU). Each polymer type was dissolved in a suitable solvent and an internal standard was utilized for quantification. Detection and quantification limits for each polymer type were established in two ways: (1) by using an equation based on proton signals and an internal standard with known concentration and (2) by using the LOQ based on the signal-to-noise ratio. Both data sets were compared and showed that using the internal standard (method 1) results in more accurate and lower concentration limits in the range of 0.2–8 µg mL−1 for all six polymer types, while the LOQ based on the SNR (method 2) gives consistently higher concentration limits (1–10 µg mL−1). The research shows the accuracy, efficacy, and reliability of quantitative NMR spectroscopy for polymer analysis in these concentration ranges compared to established quantifying methods, such as, PyGC/MS, FTIR, or Raman spectroscopy.

Edible Swiftlet Nest (ESN) is a swiftlet's saliva product that contains many beneficial compounds. However, improper washing leaves behind toxic nitrite content. To ensure its absence, sensitive and accurate methods are needed, such as UV-Vis spectrophotometry. However, long analysis time and complicated maintenance, limit its further use. In this research, cyclic voltammetry was developed as an alternative analysis method for nitrite content in ESN. The results show that the LOD and LOQ of this method are 0.658529 ppm and 1.995544 ppm, respectively. Compared to this value, analysis using UV-visible spectrophotometry shows lower LOD and LOQ values, respectively 0.061579 ppm and 0.186602 ppm. [ABSTRACT FROM AUTHOR]

UV Spectrophotometric method has been developed to determine Gliclazide in bulk pure and tablet forms. It is a simple, accurate, reproducible, rapid and less time-consuming method. The maximum wavelength of the drug was found to be 232nm. Beer Lamberts' law was obeyed in the concentration range of 2-20 µg/ml. (LOD)The limit of detection and limit of qualification (LOQ) was found to be 0.16 µg/ml and 0.50 µg/ml from this method per cent recovery of the drug was found to be 99.30% which indicates no interaction of the excipients. This method was found accurate, simple, precise and rapid for determination of tablet dosage form. [ABSTRACT FROM AUTHOR]

A novel, sensible, rapid, reliable and economical analytical hyphenated LC-MS/MS method has been developed as a key for the safety surveillance in chronic leukemia patients, and as a part of therapeutic drug monitoring of imatinib mesylate in human saliva. Imatinib mesylate or imatinib methane sulfonate is a tyrosine kinase inhibitor, apoptosis inducer and also known to be an anticoronaviral agent. Imatinib mesylate is a monomesylate salt of imatinib used for the treatment of gastrointestinal tumors and chronic myelogenous leukemia, and also in other complex malignancies. The lmax of imatinib mesylate was observed at 258 nm by UV spectrometry, establishing a very good linearity along with sensitivity. The detection limit (LOD) =0.2925 µg mL-1 and quantitation limit (LOQ)= 0.8977 µg mL-1 were obtained from the linear concentrations taken in the range of 2-12 µg mL-1. The correlation coefficient (r2) found was 0.999. The method validation parameters according to ICH Q2 (R1) were performed. The developed method described here, UPLC-MS/MS, was found to be novel, sensitive and rapid with improved results when successfully tested for human saliva samples without significant differences in the steady state imatinib mesylate concentrations. Current method could overcome the safety issues during therapeutic drug monitoring and pharmacokinetic behavior of the drug when tested clinically. [ABSTRACT FROM AUTHOR]

The present research work discusses the development and validation of a UV spectrophotometric method for butorphanol tartrate. Simple, accurate and cost efficient spectrophotometric method has been developed for the estimation of butorphanol tartrate in tablet dosage form. The optimum conditions for the analysis of the drug were established. The maximum wavelength (λ max) was found to be 278nm. The percentage recovery of butorphanol tartrate was in the 100.016±0.68. Beers law was obeyed in the concentration range of 2-12µg/ml. Calibration curves shows a linear relationship between the absorbance and concentration. The line equation y = 0.0674x - 0.0057 with r2 of 0.9998was obtained. Validation was performed according to ICH guidelines for linearity, accuracy, precision, LOD and LOQ. The sample solution was stable up to 36 hours. The proposed method may be suitable for the analysis of butorphanol tartrate in tablet formulation for quality control purposes. [ABSTRACT FROM AUTHOR]

Maize (Zea mays L.) is sown for fodder and silage in the spring season (February-June) by commercial dairy farmers in northwestern India and its sowing time varies under different crop rotations. A 2-year field study was conducted during 2020-21 and 2021-22 to study the weed flora and quantification of atrazine residue in green fodder and silage of spring maize sown in different maize-based rotations. Spring maize was grown as fodder for silage making in three crop rotations {maize – oat (Avena sativa L.) or toria (Brassica rapa ssp. oleifera) or rapeseed (Brassica napus L.) – spring maize}. Winter season weeds namely Chenopodium album L., Coronopus didymus (L.) Sm. and Rumex dentatus L. and spring season weeds namely Oenothera laciniata Hill and Gnaphalium purpureum L. were not reported in spring maize grown in maize-rapeseed-spring maize rotation. During 2022, growth of Digitaria sanguinalis (L.) Scop. and Cyperus rotundus L. was favoured in maize-rapeseed-spring maize rotation than in other two crop rotations. After 60 days of application, atrazine residue level of 0.01 mg kg−1 was found in green fodder of spring maize grown in maize-oat-spring maize and maize-toria-spring maize rotations, while it was below limit of quantification (LOQ < 0.01 mg kg−1) in green fodder of spring maize grown in maize-rapeseed-spring maize. Atrazine residue in spring maize fodder at harvest and in silage is below LOQ in three crop rotations. Thus, atrazine can be safely used in spring maize grown for silage making. [ABSTRACT FROM AUTHOR]

The development and expansion of analytical methods for per- and polyfluoroalkyl substances (PFAS) in food are essential for the continued monitoring of the United States (US) food supply and assessments of dietary exposure. In March 2022, the European Union Reference Laboratory for Halogenated Persistent Organic Pollutants in Feed and Food (EURL POPs) released a guidance document covering priority PFAS of interest, including analytical method parameters and limits of quantification (LOQs). As a result, the Food and Drug Administration (FDA) began method extension work to incorporate ten new additional analytes to method C-010.02 including long-chain perfluorosulfonic acids, fluorotelomer sulfonates, and perfluorooctane sulfonamide. Four long-chain carboxylic acids were also validated across all foods, which were previously added to C-010.02 but only validated in seafood. In December 2022, the European Union published Commission Regulation 2022/2388, establishing maximum levels for perfluorooctane sulfonic acid (PFOS), perfluorooctanoic acid (PFOA), perfluorononanoic acid (PFNA), and perfluorohexane sulfonic acid (PFHxS) in certain foodstuffs, primarily fish, molluscs, crustaceans, and eggs. As a result, the FDA method was evaluated for performance in reaching LOQs defined in Commission Regulation (EU) 2022/1431. The FDA method was found to be able to reach all required LOQs for analytes in matrices with established maximum levels. Currently, method detection limits (MDLs), which are used by the FDA as the lower limit for reporting PFAS in surveillance samples, were in the same range as defined indicative levels. With further method modifications, required LOQs could be met in fruits, vegetables, and milk. Reaching the lower targeted LOQs for these food matrices will require moving the method to an instrument that can provide increased signal:noise gains at the lower limits of quantification. [ABSTRACT FROM AUTHOR]

Background and Objectives: Plantago is a diverse genus of the Plantaginaceae family. Plantago lanceolata L. (P. lanceolata) and Plantago major L. (P. major) are used commercially worldwide as a traditional treatment for many diseases. A sensitive, simple, and reliable high-performance liquid chromatography (HPLC) method was developed to simultaneously quantify the three active ingredients: apigenin, catalpol, and gallic acid in P. lanceolata and P. major. Methods: HPLC analysis was carried out using C8 and C18 columns. The mobile phase comprised acetonitrile, orthophosphoric acid, or formic acid (different ratio V/V) with flow rates of 0.4, 0.8, and 1 mL/min. The eluted peaks were detected at 204, 210, 256, and 330 nm. The crude extracts were separated using the liquid-liquid extraction method. Results: HPLC analysis was performed using the C8 column with the mobile phase consisting of acetonitrile–orthophosphoric acid (1:1%) at a 1 mL/min flow rate. The detection of the eluted peaks was observed at 204 nm. Using this protocol, the detection and quantification limits for apigenin, catalpol, and gallic acid were 0.007 and 0.022 μg/mL, 0.04 and 0.14 μg/mL, 0.02 and 0.073 μg/mL, respectively. The calibration curve’s correlation coefficient indicated good linearity (r>0.9996, 0.9991, and 0.9978), with average recoveries for the three compounds between 100.02, 95.98, and 108.30%, respectively. Meanwhile, the intra-day and inter-day accuracy averages ranged from 100.07 to 99.95%, respectively. The results showed that using dichloromethane extracts of Plantago species leaves produced the highest yield of apigenin (1.08 and 0.58 μg/mg). At the same time, gallic acid was more abundant in methanolic, butanol, and aqueous extracts of P. lanceolata (3.33 μg/mg) and P. major (3.95, 4.34, and 4.72 μg/mg). The aqueous extract of P. lanceolata leaf and P. major root also showed more catalpol content (9.339 and 2.451 μg/mg). Conclusion: The developed method indicated reliable results with reproducibility, high accuracy in an analytical run, repeatability, acceptable intermediate precision, reproducibility, and stability of these working solutions. To the best of our knowledge, this study is the first report for the simple, simultaneous quantification of three compounds in Plantago spp. using HPLC.

The proposed HPLC Method was found to be simple, precise, accurate and economical for the estimation of dutasteride in Bulk and tablet dosage form. The present work, developed HPLC method was found suitable and validated. Luna - C-18 (250 mm x 4.6 mm, 20 µL) column was used for the assay. Mobile phase was Acetonitrile and Water in the ratio 80:20. Linearity was established in the range of 5-100 µg/ml with a coefficient correlation of 0.9998 and eluents were monitored at 242 nm and at 1 ml/min. flow rate. The Retention time was found to be 5.9 min. The efficiency of the column, expressed as the number of theoretical plates for six replicate injections was 11566 ± 119.695 (%CV1.03%) and USP tailing factor was 1.25 ± 0.012 (%CV 0.79). The regression equation for the calibration plot was Y = 0.0618 X - 0.008. Intra-day precision from 0.166 to 1.449 and Inter-day precision from 0.186 to 1.449. The% recovery of dutasteride from API and dosage form were 100.70% and 99.66%. The drug was subjected to stress conditions such as Oxidative and Photodegradation, Considerable degradation was found to occure in acidic and basic medium on heating at 100°C but no degradation was observed at room temperature. The drug was exposed to 10% H2O2{heating at 100°C forming degradation product at RT: 2.557}. The LOD and LOQ was 0.257µg and 0.779 µg respectively. When the flow rate was reduced, the retention time of dutasteride increased. The assay result with analyst #1 and Analyst #2 were % Assay = 98.40% (%RSD = 0.13%) and % Assay = 99.07% (%RSD =0.53) respectively. Robustness and ruggednesswasobserved that results were well within acceptance limits of 98-102%, with %RSD ±2.0%, indicating the method is rugged and provides consistent and reliable results which are not affected by small changes in experimental conditions. This method can be used for routine analysis of dutasteride. Running Title: A New Method Development and Validation of 5a-Reductase inhibitor using R-HPLC. [ABSTRACT FROM AUTHOR]

Humans are frequently exposed to Quaternary Ammonium Compounds (QACs). QACs are ubiquitously used in medical settings, restaurants, and homes as cleaners and disinfectants. Despite their prevalence, nothing is known about the health effects associated with chronic low-level exposure. Chronic QAC toxicity, only recently identified in mice, resulted in developmental, reproductive, and immune dysfunction. Cell based studies indicate increased inflammation, decreased mitochondrial function, and disruption of cholesterol synthesis. If these findings translate to human toxicity, multiple physiological processes could be affected. This study tested whether QAC concentrations could be detected in the blood of 43 human volunteers, and whether QAC concentrations influenced markers of inflammation, mitochondrial function, and cholesterol synthesis. QAC concentrations were detected in 80 % of study participants. Blood QACs were associated with increase in inflammatory cytokines, decreased mitochondrial function, and disruption of cholesterol homeostasis in a dose dependent manner. This is the first study to measure QACs in human blood, and also the first to demonstrate statistically significant relationships between blood QAC and meaningful health related biomarkers. Additionally, the results are timely in light of the increased QAC disinfectant exposure occurring due to the SARS-CoV-2 pandemic.Main findingsThis study found that 80 % of study participants contained QACs in their blood; and that markers of inflammation, mitochondrial function, and sterol homeostasis varied with blood QAC concentration.

Chemo-selective heterogeneous catalytic hydrogenation was employed to synthesise 6-amino-N-methyl-2-quinolone (AMQ) and 6-amino-N-ethyl-2-quinolone (AEQ) to establish its structure-activity relationship (SAR) by 1H NMR,13C NMR, FT-IR, LC-MS/MS. AMQ (MIC = 18.2, 16.5 mg/mL) and AEQ (MIC = 19.2, 20.5 mg/mL), were more effective against Aspergillus niger and Aspergillus flavous. Both were tested on tomato (Solanum lycopersicum L.) plants to assess residual profiles, dissipation patterns, and yield effects. Acetonitrile and methanol (9.5:0.5, v/v), and modified buffer QuEChERS were used for extraction and analysed by LC-MS/MS. For AMQ, LOD and LOQ were 0.0065 and 0.017 mg kg−1, respectively, whereas, for AEQ, 0.0031 and 0.017 mg kg−1. The 5-point calibration curves of both compounds were constructed with R2 in the range of 0.99. Average recoveries at LOQ and higher ranged from 82.50 -114.27%. According to first-order kinetics, the half-lives (T1/2) for the T1 and T2 of AMQ were 2.11, and 2.34 days, and for AEQ were 1.66 and 2.13 days, respectively. Estimated pre-harvest intervals (PHIs) for AMQ and AEQ were 8,6 days (T1), and 11,10 days (T2) respectively. Their application enhanced fresh tomato production 21.36–26.55%. Developed compounds have excellent in vitro and in vivo fungicidal action and could treat plant fungal infections.

The goal of the present investigation was to develop and validate the UV-spectrophotometric technique for the quantitative estimation of ripasudil hydrochloride hydrate in pure and ophthalmic formulations. Ripasudil hydrochloride hydrate is a novel drug molecule that has been used to treat glaucoma and ocular hypertension. It was licensed for therapy in Japan for the first time in September 2014. Until now, only an HPLC analytical method for determining it in dosage forms and biological fluids has been disclosed. The objective of this research was to screen a solvent system in which ripasudil hydrochloride hydrate can be completely solubilized, then develop and validate a simple, accurate, precise, and cost-effective UV-spectrophotometric method for estimating ripasudil hydrochloride hydrate in the pure and ophthalmic formulations in accordance with International Conference on Harmonization (ICH) recommendations. The current method is simple, quick, accurate, precise, and cost-effective. Ripasudil hydrochloride hydrate is soluble in HPLC-grade distilled water, so it was used as a solvent to form the solution. The subsequent solution was scanned within the UV range (200–400 nm). The λmax of ripasudil hydrochloride hydrate was found to be 278 nm. Beer's law is valid within the 10 to 50-μg/mL concentration range. The developed analytical approach was extensively validated as per ICH guidelines for linearity, accuracy, precision, robustness, detection limit, and quantitation limit. Linearity was obtained within the 10 to 50-μg/mL range with a correlation coefficient of 0.9981. Limit of detection and limit of quantitation were found to be 0.0785 and 0.2355 μg/mL. The technique presented good recovery and reproducibility; thus, the proposed technique might be employed for regular investigation of ripasudil hydrochloride hydrate in the pure and ophthalmic formulations. [ABSTRACT FROM AUTHOR]

Assessment of the adequacy of a proposed linear calibration curve is necessarily subjective in chemical analysis. If the outlier points in calibration are not identified and discarded, the constructed model will not have much validity and does not warrant the accuracy and precision of prediction step. Recognizing of influential points, outlier data, and discarding them is one of the steps in data processing that has been considered in various sciences. The outlier points can arise from (I) bad design of calibration set and (II) gross error in doing experiments. Therefore, we aimed to extract a map that recognizes the following issues: (A) the existence of data with high regression coverage that is far from the rest and will strongly affect the accuracy of the calibration equation, high leverage points; (B) large error in the experimental process: The recorded signal does not match the desired concentration; and (C) points with a concentration lower than the limit of quantification, which is calculated by considering the standard error of regression instead of the standard deviation of blank. The efficiency of the proposed roadmap will be reviewed, and this will give a new perspective on the calibration equation to avoid common mistakes in analytical chemistry. To achieve the above goal, visual and statistically significant tests will be used and all tests will be performed in a simple Microsoft Excel environment. [ABSTRACT FROM AUTHOR]

Industrial hemp (Cannabis sativa L.) is known mainly for the psychoactive compound delta-9-tetrahydrocannabinol (THC) and cannabidiol (CBD). In addition to the mentioned compounds, hemp is also rich in other medicinal and useful substances found in the essential oil, including terpenes. Terpenes are compounds found in plants, herbs, fruits and vegetables and are responsible for their taste and smell. The field of terpene research has recently grown mainly due to their positive effects on the human organism and their use in agronomy. The chemotype of cannabis determines the composition of essential oil components and depends on the variety and the growing area. At the Slovenian Institute of Hop Research and Brewing, we optimized and validated a method for determining the composition of hemp essential oils. The validation process included checking the selectivity, linearity, accuracy, precision, determination of the limit of detection and the limit of determination on a new Agilent 8890 GC. With this, we have reduced time, needed for the analyses. [ABSTRACT FROM AUTHOR]

Here, we present a direct comparison of different dyes and assays for the determination of protein concentrations. We compared the classical Bradford assay with two modern assays based on the fluorogenic dyes QuDye and ProteOrange and showed that the Bradford reagent achieved excellent results in the determination of protein concentrations as compared with more modern rivals. We also showed that standard approaches for determining the limit of detection (LoD) and limit of quantification (LoQ) may not work correctly with the tested dyes. We proposed a new approach that extends the standard algorithm for LoD and LoQ determination. This approach works well with both classical colorimetric and fluorogenic dyes, as well as with nontrivial fluorescent probes. [ABSTRACT FROM AUTHOR]

Background: In 2017, the European Commission renewed the approval of glyphosate (GLY) but only for five years. GLY remains one of the most controversial and studied molecules. Method: A simplified method was tested for the determination of GLY in white rice (WR) and brown rice (BR), after extraction only with a methanol solution, by liquid chromatography coupled with inductively coupled mass triple quadrupole (HPLC-ICP-MS/MS) with a PRP-X100 anionic column. After performing a test on groundwater, the quantification of GLY in WR and BR was validated in terms of the LOD, LOQ, accuracy, precision, linearity, and the matrix effect. Results: The LOD was 0.0027 mg kg−1 for WR and 0.0136 mg kg−1 for BR. The LOQ was 0.0092 mg kg−1 for WR and 0.0456 mg kg−1 for BR. The mean recoveries were within 76–105% at three fortification levels. The relative standard deviation for the analysis (five replicates for three spike levels) was < 11% for both matrices. A linear response was confirmed in all cases in the entire concentration range (R2WR = 1.000 and R2BR = 0.9818). Conclusion: The proposed method could be considered useful for the determination of GLY in different types of rice and designed and adapted for other cereals. The matrix effect, quantified in BR matrix extraction, could be avoided by using a matrix-matched calibration line. [ABSTRACT FROM AUTHOR]

The goal of this study was to validate the analytical technique for determining the immediate development of lead (Pb), cadmium (Cd), mercury (Hg), and arsenic (As) in various Indian seafood products. According to Commission Regulation (EC) 333/2007, various marine foods, including crustaceans, cephalopods, and fish species, were employed for the validation of the developed method by ICP-MS. HNO3 and H2O2 were combined to prepare the sample during microwave digestion. Specificity/selectivity, linearity, LOD, LOQ, precision-repeatability and reproducibility, accuracy-recovery, robustness, and fitness studies were used to validate the approach. The maximum RSD value and Horrat value (HorRat) for the within-lab reproducibility for all analytes (Pb, Cd, Hg, and As) in marine food were 5% and 1 respectively. The mean recovery for all analytes examined at three spiking levels (0.5, 1 & 1.5 of the permitted limit) was between 92.67 and 107.33%.Whereas limit of detection (LOD) values for Pb, Cd, Hg and As were 0.018 μg/g, 0.032 μg/g, 0.031 μg/g and 0.034 mg/kg for repeatability 6% and <1 respectively. 0.061 μg/g, 0.127 μg/g, 0.0.103 μg/g and 0.101 μg/g respectively, were the limit of quantitation (LOQ) values. At a 95% confidence level, the method's relative extended measurement uncertainty (k=2) was 9%. In fact, the developed method's precision was examined by taking part in LGC proficiency testing (round 253, sample 742); the outcomes (Z score, i.e. < 1) showed that this analytical method could be used for the routine analysis of these four toxic metals in seafood with acceptable analytical performance in the laboratory. [ABSTRACT FROM AUTHOR]

Quercetin possesses low solubility and decreases oral bioavailability. One way to increase the bioavailability of quercetin is by formulating a self-nanoemulsifying drug delivery system (SNEDDS). In vitro dissolution testing of SNEDDS needs to be carried out using a validated analytical method. This study aims to validate the quercetin analytical method in in vitro dissolution testing. Validation was carried out with two solvents, namely hydrochloric acid buffer pH 1.2 (HCl-1,2) and phosphate buffer pH 6.8 (PO-6.8). It tested some parameters, including linearity, detection limit (LoD), quantification limit (LoQ), accuracy, and precision. The quercetin calibration curve for both solvents has a value of r≥0.999. The LoD at HCl-1,2 and PO-6,8 were 0.26 ppm and 0.27 ppm, respectively. The LoQ of HCl-1,2 and PO-6,8 were 0.86 ppm and 0.91 ppm, respectively. The percentage recovery in both solvents was in the range of 80-110%. The relative standard deviation of the two solvents was less than 7.3%. The quercetin analytical method has been successfully validated as indicated by the results of linearity, detection limit, quantification limit, accuracy, and precision that met the requirements

[Display omitted] • Exploration of anticancer dipeptide Aurantiamide acetate from the seeds of Brassica species. • Traditional 'Kolhu' method showed remarkable efficiency in extracting dipeptides. • Phytometabolite profiling was done by a validated UPLC-MS/QToF analytical method. • This novel method was found to be robust for the effective quantitation of dipeptides. Mustard (Brassica spp.) is one of the world's oldest condiments in the food basket, which holds a significant place in the global culinary landscape due to historical prominence and perceived health benefits. This study explores the extraction of oils from Mustard seeds by employing traditional 'Kolhu' method, modern supercritical fluid, and solvent extraction techniques. This study, for the first-time, identified Aurantiamide acetate, a potent anti-cancer dipeptide in Mustard seeds using ultra-performance liquid chromatography-mass spectrometry coupled with quadrupole time-of-flight (UPLC/MS-QToF) analytical platform. The analytical methodology was meticulously validated encompassing optimal parameters such as limit of detection, limit of quantification, precision, accuracy, linearity and robustness, within the range. Interestingly, 'Kolhu' method of oil extraction exhibited better yield of Aurantiamide acetate, suggesting superior efficiency of traditional methods. This study accentuates the importance of classical extraction methods, used traditionally, and emphasizes that naturally occurring substances indeed could be harnessed for better health. [ABSTRACT FROM AUTHOR]

Diclofenac (DCL) is a nonsteroidal anti‐inflammatory commonly prescribed to treat inflammatory joint diseases and mild to moderate pain. DCL residues have often been detected in freshwater environments and it belongs to the list of emerging pollutants (EPs) because of the risk it presents for health and environment. Many studies have described the potential effects of DCL on organisms when exposed to environmental levels ranging from a few ng L−1 to tens of μg L−1 in surface water. Until now, its detection essentially depends on conventional techniques, such HPLC and GC/MS. Although these analytic techniques are very robust, they are expensive, require experts, and are not portable. Electrochemical sensors are an attractive alternative. They provide many benefits over thermal, optical, and piezoelectric detection including ease of use, rapidity, cost‐effectiveness, high sensitivity and selectivity, ease of miniaturization and robustness. The aim of this review is to report electrochemical methods used for the detection of DCL and to describe strategies for improving performances of each sensors. [ABSTRACT FROM AUTHOR]

Histamine is commonly present in food containing proteins, like in mackerel. Consuming fish is imperative for the improvement of human muscles. Nevertheless, some studies reported ingesting fish containing histamine more than 50 mg·kg-1 can cause toxicity. This study analyzed and determined the composition of histamine in mackerel and its products commonly consumed in Malaysia, especially on the East Coast of Malaysia. These included processed mackerel such as canned products, satay (skewed fish) and keropok lekor (fish cake/ cracker). Histamine analysis was performed using High Performance Liquid Chromatography (HPLC) equipped with a fluorescence detector. A derivatizing reaction was applied to increase the sensitivity of HPLC to histamine using 9-flourenilmethylchloroformate (FMOC-Cl). The chromatographic separation was achieved in 15 min. Method validation was in accordance to Commission Decision 657/2002/CE. The linear range was at 0.16 - 5.00 µg·mL-1 (histamine) with the LOD at 0.10 µg·mL-1 and LOQ at 0.30 µg·mL-1. Method applicability was checked on seven real samples involving raw, cooked, and dry products, yielding acceptable recovery. [ABSTRACT FROM AUTHOR]

The increasing use of gibberellic acid (GA3) to promote fruit growth and yield has necessitated research into its trace level determination and estimation in harvested product. The phytohormone has increased the tomato yield (tonne ha−1) up to 24.7% with uniform fruit shape, size colour and lustre. A fast, simple, high-throughput analytical method was standardised based on electrospray ionisation — liquid chromatography-tandem mass spectrometry (LC–MS/MS). The samples were extracted using acidified (1% formic acid) methanol. The method was validated as per the SANTE/12682/2019 guidelines. The limits of detection (LOD) and quantification (LOQ) were 0.01 and 0.05 mg kg−1. The average recoveries at LOQ and higher levels were in the range of 86–108% with relative standard deviation (RSD) < 20%. The validated method was successfully applied under field condition by following first-order kinetics with half-lives (T1/2) 1.76 days (recommended dose) and 1.99 days (double dose). The estimated pre-harvest intervals (PHIs) were 6 days (recommended dose) and 8 days (double dose). Studies on dietary risk assessment concluded that even after spray of GA3 at recommended dose, the harvested produce (tomato) could be consumed safely. [ABSTRACT FROM AUTHOR]

Background: In 2017, the European Commission renewed the approval of glyphosate (GLY) but only for five years. GLY remains one of the most controversial and studied molecules. Method: A simplified method was tested for the determination of GLY in white rice (WR) and brown rice (BR), after extraction only with a methanol solution, by liquid chromatography coupled with inductively coupled mass triple quadrupole (HPLC-ICP-MS/MS) with a PRP-X100 anionic column. After performing a test on groundwater, the quantification of GLY in WR and BR was validated in terms of the LOD, LOQ, accuracy, precision, linearity, and the matrix effect. Results: The LOD was 0.0027 mg kg−1 for WR and 0.0136 mg kg−1 for BR. The LOQ was 0.0092 mg kg−1 for WR and 0.0456 mg kg−1 for BR. The mean recoveries were within 76–105% at three fortification levels. The relative standard deviation for the analysis (five replicates for three spike levels) was < 11% for both matrices. A linear response was confirmed in all cases in the entire concentration range (R2WR = 1.000 and R2BR = 0.9818). Conclusion: The proposed method could be considered useful for the determination of GLY in different types of rice and designed and adapted for other cereals. The matrix effect, quantified in BR matrix extraction, could be avoided by using a matrix-matched calibration line.

The patients from Type 2 diabetes sometimes from increased lipid levels and increased hypertension also. These conditions may cause several complications and it requires multidrug therapy in single dose regimen. So combination of Rosuvastatin and Tenegliptin fulfill these requirements with minimum risk factors. The aim of the present study was to develop and validate a simple, rapid and reproducible gradient high performance reverse phase liquid chromatography method for the estimation of Rosuvastatin and Tenegliptin in bulk drug sample and in synthetic mixture using Luna C18 100A°(250mm x 4.6mm i.d. 5 µm) column kept at 25°C and UV detection at 240nm. The compounds were eluted gradiently at a flow rate of 1.0ml/min. The average retention times for Teneligliptin and Rosuvastatin were 2.583 and 5.458 min, respectively. The calibration curves were linear (r² > 0.9999) over the concentration range 10-200µg/ml for Teneligliptin and 10-200µg/ml for Rosuvastatin. No spectral or chromatographic interferences from formulation excipients were found and hence it was successfully applied for the determination of Teneligliptin and Rosuvastatin in bulk and in synthetic mixture. The accuracy of the proposed method was determined by recovery studies and found to be 98-101%. The proposed method was validated and results conformed to ICH parameters. [ABSTRACT FROM AUTHOR]

A rapid, simple, sensitive, and selective liquid chromatography–tandem mass spectrometry (LC–MS) test method was developed and validated for the trace level determination of 4‐chlorobutyl‐(S)‐[4‐chloro‐2‐(4‐cyclopropyl‐1,1,1‐trifluoro‐2‐hydroxy‐but‐3yn‐2‐yl)phenyl] carbamate (4‐CTHC). 4‐CTHC is a potential genotoxic impurity in efavirenz drug substance and the acceptable level is 2.5 μg ml−1 with respect to analyte concentration according to ICH M7(R1) Multidisciplinary Guidelines M7(R1). The LC–MS/MS analysis of 4‐CTHC impurity was carried out on a Kinetex C18 (150 × 4.6 mm, 5.0 μm) column. In this test procedure, the mobile phase was prepared with buffer (0.1% formic acid in water) and acetonitrile in the ratio of 1:3 (v/v). The method set flow rate was 0.4 ml min−1. The method was developed with a short run time of <10 min. Selective ion monitoring acquisition mode and negative polarity electrospray ionization mode were used as an MS method to quantify genotoxic impurities at 422.25 Da. The method showed linearity in a range of 0.64–3.71 μg ml−1 with a correlation coefficient of 0.9992. The RSD for intra‐day and inter‐day precision was found to be <5%. The method's accuracy was in the range of 106.5–112.4% for the genotoxic impurity of 4‐CTHC. The procedure was validated as per the current ICH Q2 (R1) guidelines and proved suitable for stability testing in the quality control laboratory for pharmaceutical preparations. [ABSTRACT FROM AUTHOR]

New methods for the analysis of azithromycin (AZM) have been devised, employing direct fluorescence and spectrophotometric techniques. This research focused on the development and validation of these methods, especially based on the formation of an ion-pair complex with fluorescein isothiocyanate (FITC). The resulting complex enhanced the fluorescence intensity at a wavelength of 520 nm and the absorbance at 480 nm. The impact of different solvent compositions was investigated, with methanol and a 1:1 mixture of methanol and Milli-Q proving to be the most sensitive. The optimal FITC concentration was determined as 50 µg/ml, and the molar ratio of the AZM-FITC ion-pair complex was determined to be 1:1. Notably, an instantaneous increase in fluorescence intensity was observed, eliminating the need for incubation. The developed methods were validated for sensitivity, accuracy, and precision, with the fluorescence-based method demonstrating superior sensitivity and precision compared to the spectrophotometric method. Under optimum conditions, the fluorescence-based method achieved a linear range of 0–31.25 µg/ml with a limit of detection (LOD) of 0.41 µg/ml and a limit of quantification (LOQ) of 1.23 µg/ml., In contrast, the spectrophotometric method had an LOD of 0.82 µg/ml and an LOQ of 2.49 µg/ml. Additionally, the fluorescence-based method exhibited a narrower recovery range in artificial urine samples, suggesting higher precision in complex matrices. Overall, these methods offer rapid and sensitive AZM analysis with potential applications in diverse matrices such as biological samples post-extraction. • Residual trace azithromycin elevates antimicrobial resistance. • Direct optical detection of azithromycin in urine. • Azithromycin-fluorescein isothiocyanate ion pair complex. • Fluorescence-based detection of azithromycin using fluorescein isothiocyanate. • Spectrophotometric detection of azithromycin using fluorescein isothiocyanate. [ABSTRACT FROM AUTHOR]

In the pharmaceutical industry, the unexpected appearance of crystalline forms could impact the therapeutic efficacy of an Active Pharmaceutical Ingredient (API). For quality control, a thorough qualitative and quantitative monitoring of pharmaceutical solid forms is essential to ensure the detection and the quantification of crystalline forms, wither different or with the same chemical composition (polymorphs) at a low detection level. The purpose of this paper was to review and highlight the importance of choosing adequate solid-state techniques for detection and quantification APIs that present polymorphism – based on limits of detection (LOD) and quantification (LOQ), pharmacopeias specifications, international guidelines and studies reported in the literature. To this study, the powder X-ray diffraction (PXRD), differential scanning calorimetry (DSC), Infrared and Raman spectroscopies and solid-state nuclear magnetic resonance (NMR) were the solid-state techniques analyzed. Additionally, the Argentine, Brazilian, British, European, International, Japanese, Mexican and the United States of America pharmacopeias were reviewed. Based on the analysis performed, the advantages and disadvantages of these techniques, as well as the LOD and LOQ values of APIs were reported. In comparison to these solid-state techniques, reference material used for identification analyses should be previously identified with the corresponding polymorph. Without this previous procedure, the patterns, the spectra, and DSC curves of the reference material can only be used to confirm the mixture of solid forms, not being able to specify which polymorphs are contained in the sample. A major advantage of PXRD is the use of the calculated diffraction patterns obtained from the Crystallographic Information Frameworks (CIFs) files which could be used as a reference pattern without any other information, assistance technique, or physical standards. Regarding the quantification aspect, different pharmacopeias suggest various methods such as the PXRD combining with Rietveld method, which can be used to obtain lower LOD values for minority phases in the mixture of different substances without the need for a calibration curve. Raman spectroscopy can detect polymorphs in small particles and solid-state NMR spectroscopy is a powerful technique for quantification not only crystalline but also crystalline-amorphous mixtures. Finally, this review intends to be a useful tool to control, with efficiency and accuracy, the polymorphism of APIs in pharmaceutical compounds. [Display omitted] • Critical analyses of different analytical solid-state techniques to improve quality control and monitoring polymorphs. • Limit of detection and quantification of analytical solid-state techniques. • Comparison of information provided from pharmacopeias about identification and quantification analysis of polymorphisms. • Advantages and disadvantages of different solid-state techniques used for identification and quantification analyses. [ABSTRACT FROM AUTHOR]

Rizwan Wahab,1,2,* Neha Kaushik,3,* Farheen Khan,4 Nagendra Kumar Kaushik,5 Su-Jae Lee,3 Eun Ha Choi,5 Abdulaziz A Al-Khedhairy1 1Zoology Department, College of Science, King Saud University, Riyadh 11451, Saudi Arabia; 2Al-Jeraisy, Chair for DNA Research, King Saud University, Riyadh 11451, Saudi Arabia; 3Department of Life Science, Hanyang University, Seoul 04763, South Korea; 4Chemistry Department, Faculty of Science, Taibah University, Yanbu 42353, Saudi Arabia; 5Plasma Bioscience Research Center/Applied Plasma Medicine Center, Department of Electrical and Biological Physics, Kwangwoon University, Seoul 01897, South Korea *These authors contributed equally to this work Background: Over the past several decades, the incidence of solid cancers has rapidly increased worldwide. Successful removal of tumor-initiating cells within tumors is essential in the field of cancer therapeutics to improve patient disease-free survival rates. The biocompatible multivarient-sized gold nanoparticles (MVS-GNPs) from quantum dots (QDs, Methods: Herein, MVS-GNPs synthesized and characterized by means of X-ray diffraction pattern (XRD) and transmission electron microscopy (TEM) techniques. Afterwards, interaction of these GNPs with glioma stem-cell like cells along with cancer cells were evaluated by MTT, cell motility, self-renewal assays and biostatistics was also applied.Results: Among these GNPs, G-QDs contributed to reduce metastatic events and spheroid cell growth, potentially blocking the self-renewal ability of these cells. This study also uncovers the previously unknown role of the inhibition of CTNNB1 signaling as a novel candidate to decrease the tumorigenesis of glioma spheroids and subsequent spheroid growth. The accurate and precise biostatistics results were obtained at quantify level.Conclusion: In summary, G-QDs may exhibit possible contribution on suppressing the growth of tumor-initiating cells. These data reveal a unique therapeutic approach for the elimination of residual resistant stem-like cells during cancer treatment. Keywords: multivarient gold nanoparticles, epithelial-mesenchymal transition, solid tumor, brain cancer, self-renewal, cellular movement, biostatistics

A Precise and feasible rapid reverse phase high-performance liquid chromatographic (RP-HPLC) method has been developed and validated for simultaneous estimation of antiemetic drug Ondansetron HCL in bulk drugs and pharmaceutical dosage form. The separation was accomplished Agilent technology HPLC AGILET (1100) With Auto Sampler on C-18 (id 4.6 x 150 mm, 2.5 µm) column with a mobile phase consisting of Methanol: 0.1 % Ortho-phosphoric acid Water (50:550 v/v) at a flow rate of 0.7 mL/min. The eluents were monitored at 248 nm. The retention time for Ondansetron HCL was 2.486min, respectively. The method was validated with respect to system suitability, linearity, precision, accuracy, specificity, limit of detection (LOD), limit of quantification (LOQ), robustness and ruggedness The Ondansetron HCL followed linearity in the concentration range of 5-25 µg/mL (r2 = 0.999). The amount of drug estimated by proposed method was found to be in good agreement with label claim. The developed method was validated for sensitivity, accuracy, precision. The LOD and LOQ values were found to be 0.05314 & 0.1610µg respectively for Ondansetron HCL. These data show that method is sensitive for the determination of Ondansetron HCL. The developed method with good symmetry, successfully applied for determination of Ondansetron hydrochloride in its pharmaceutical dosage form. [ABSTRACT FROM AUTHOR]

Key issues related to determining the limit of quantification (LOQ) in practice are considered. Requirements to the value of LOQ and its precision and accuracy are formulated. It is shown that the use of a calibration curve for LOQ determination may result in erroneous conclusions for impurity determination methods. Answers to a number of questions relevant to practice are given. The precision of the LOQ value should always be checked if the LOQ is determined from a calibration curve. A typical requirement for LOQ precision is RSD ≤ 5.0%. An RSD ≤ 10% is acceptable in exceptional cases of a very low LOQ concentration. For this, the validation documentation should visually confirm the acceptability of the LOQ value by a chromatogram of a solution of the determined substance with the LOQ concentration. [ABSTRACT FROM AUTHOR]

A novel approach was used for develop and validate a rapid, accurate, and an isocratic RP-HPLC method with PDA detector for the estimation of ixazomib drug in pharmaceutical dosage forms. Ixazomib was separated using Agilent 4.6 X150 mm, 5 pm analytical column, a Waters HPLC system (USA) and a mobile phase consisting of water and acetonitrile in the ratio of 40:60 V/V. The flow rate was set to 0.7 mL/min with 10pL injection volume. The column was maintained at ambient temperature, detector was set at wavelength of 274 nm. The retention time of ixazomib was found to be 2.17 min. The system suitability parameters for ixazomib such as theoretical plates and tailing factor were found to be 4146. Linearity was established for ixazomib in the range of 50-250 pg / ml concentration levels with correlation coefficients (r2) of 0.999.The intra-and inter-day precision % RSD values were found to be 0.47 and 0.31, respectively. The limit of detection (LOD) and limit of quantification (LOQ) values were found to be 2.03 and 6.17 pg/mL respectively. The method was validated for all of the above parameters according to the International Conference on Harmonization (ICH) guidelines. This method can be used for estimation and analysis of ixazomib drug in active pharmaceutical ingredients and pharmaceuticals. [ABSTRACT FROM AUTHOR]

This technical review article focuses on determining a robust and precise lower-level sulfur detection procedure. When measuring under 0.1 ppm and approaching zero values, the limits of the instrument are pushed to separate real signal response from noise. One of the performance parameters in method validation studies is to determine these near-zero value samples reliably when the instrument works near the noise signal level. The study examined the early stages of the method development process, regarding the determination of the validation parameters limit of blank, limit of detection (LOD), and limit of quantification (LOQ). The sulfur content in diesel fuel was determined with guidance from the standard ISO 20846:2011. The average sulfur readings of a diesel test sample and blank (99% iso-octane) were measured as 3.9 and 0.0196 ppm, respectively. For a 1.5% diluted diesel test sample the mean sulfur value was measured as 0.0613 ppm and this value was verified as the LOD. For a 3% diluted diesel test sample the mean sulfur value was measured as 0.1158 ppm and this result was verified as the LOQ. The LOD and LOQ were tested for conformity. The accuracy of these tested values was checked according to EUROCHEM guidelines. [ABSTRACT FROM AUTHOR]

Competing Interests: The author declares that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

Aflatoxins, produced mainly by filamentous fungi Aspergillus flavus and Aspergillus parasiticus, are one of the most carcinogenic compounds that have adverse health effects on both humans and animals consuming contaminated food and feed, respectively. Aflatoxin B1 (AFB1) and aflatoxin B2 (AFB2) as well as aflatoxin G1(AFG1) and aflatoxin G2 (AFG2) occur in the contaminated foods and feed. In the case of dairy ruminants, after the consumption of feed contaminated with aflatoxins, aflatoxin metabolites [aflatoxin M1 (AFM1) and aflatoxin M2 (AFM2)] may appear in milk. Because of the health risk and the official maximum limits of aflatoxins, there is a need for application of fast and accurate testing methods. At present, there are several analytical methods applied in practice for determination of aflatoxins. The aim of this review is to provide a guide that summarizes worldwide aflatoxin regulations and analytical methods for determination of aflatoxins in different food and feed matrices, that helps in the decision to choose the most appropriate method that meets the practical requirements of fast and sensitive control of their contamination. Analytical options are outlined from the simplest and fastest methods with the smallest instrument requirements, through separation methods, to the latest hyphenated techniques.