Journal of Analytical Methods in Chemistry最新文献

A novel, sensitive, and efficient method was developed for the determination of paraquat in soil samples, centered on solid-phase microextraction using hollow fiber-supported ZIF-8@GO reinforced sol-gel combined with UV-Vis spectrophotometry at 257 nm. Silica-based ZIF-8@GO was synthesized through sol-gel technology by reacting tetraethyl orthosilicate (TEOS) with hydrochloric acid (HCl) as a catalyst. The resulting solution was injected into hollow polypropylene fiber segments for in situ gelation. Key microextraction parameters, such as the donor phase pH and volume, stirring rate, extraction time, and desorption conditions (solvent type and volume), were systematically studied and optimized. Under optimal conditions, the method demonstrated linearity within the range of 0.5-2000 μg L^-1, with a correlation coefficient of 0.999. The relative standard deviation for seven replicate measurements at a concentration of 600 μg L^-1 paraquat was 0.4%. A preconcentration factor of 631 and a detection limit of 0.15 μg L^-1 were achieved. Validation of the method was conducted by analyzing soil samples from various sites, yielding recoveries between 96% and 105% with low relative standard deviations, indicating its high accuracy and reliability in detecting trace levels of paraquat.

Dipeptidyl peptidase IV (DPP IV), one of the most essential peptidase, is widely distributed in various organs and tissues of the human body, which affects protein stability by acting on peptide bonds at the end of peptide chains and is further involved in physiological processes such as cellular metabolism and signaling. Recent studies have shown that DPP IV is not only involved in normal physiological processes but also closely related to various pathological processes, making it an important target for the treatment of metabolic diseases. Deciphering the relevance of DPP IV to human diseases and screening the inhibitors of DPP IV requires reliable tools, which can sense the function of this key enzyme in complex biological samples. Therefore, we aimed to construct a simple and easy-to-use assay for human DPP IV activity in a living cell system to achieve highly sensitive and selective detection of DPP IV function and further screening for its inhibitors. An easy-to-use assay for DPP IV function at the cellular level with a specific fluorescence probe toward DPP IV using a fluorescence microplate reader was the first to be established. Then, the experimental conditions were systematically optimized in terms of cell density, concentrations of probe, and incubation time. After that, the efficacy of the positive DPP IV inhibitors was evaluated by utilizing the optimized easy-to-use assay. Overall, this easy-to-use assay exhibited good precision, robustness, high throughput, and reliability. In conclusion, a straightforward and user-friendly method has been developed for detecting DPP IV activity in live cells, enabling accurate assessment of DPP IV function and efficient screening of inhibitors. This method may hold significant implications for advancing understanding of the relationship between DPP IV and disease progression, early disease diagnosis, and personalized drug therapy.

The use of human growth hormone (hGH) by athletes remains widespread despite being banned by the World Anti-Doping Agency (WADA). Current commercial ELISA kits for the determination of hGH are predominantly based on the sandwich format of this method, which allows the analysis of the whole hGH molecules, but not their fragments. The abuse of these fragments by athletes is the current trend in doping. Therefore, a competitive ELISA format is needed; however, only a limited number of kits on the market are based on this principle. Furthermore, these kits are designed to detect and quantify hGH only in blood plasma, serum or tissue cultures. When analysing a nutritional supplement containing hGH using one of these ELISA kits, a false negative result was observed. In the present work, two competitive ELISA methods for the detection of hGH in illegal nutritional supplements were developed. The development of the methods involved the selection of suitable immunoreagents and their combinations with subsequent optimisation of the conditions for their use. The methods were then characterised (with LOD 0.4 and 18.4 ng/mL, according to the primary antibody) and applied to analyse real nutritional supplements. In all 34 samples suspected of containing hGH, the hormone was detected using both ELISA methods and subsequently confirmed by LC-UV and LC-MS. Therefore, the newly developed ELISA methods could become a valuable tool for the police in identifying illegal preparations.

Saffron (Crocus sativus L.), an exceptionally valuable and expensive spice on an international scale, has become the target of a rapid increase in fraudulent practices. In an effort to decrease expenses, stigmas of safflower (Carthamus tinctorius), which closely resemble saffron, are often added to pure saffron as a typical method of adulteration. Hence, by quantifying the extent of eugenol modifications in the samples and employing ion mobility spectrometry (IMS) to identify and quantify these adulterants in saffron, the objective of this research has been accomplished. The analysis of eugenol showed a significant increase in peak intensity as the concentration of safflower increased in laboratory-prepared samples of pure saffron and safflower as well as the mixture of them (25%, 50%, 75%, and 100%, v/v). In the subsequent phase, a total of 20 saffron samples procured from nearby markets were examined under an optical microscope to identify any adulteration with safflower. Five samples, which included saffron containing safflower at varying concentrations (8.3%, 14.9%, 19.4%, 25.4%, and 33.7% W/W), were chosen for additional IMS analysis. The results showed that the peak intensity of eugenol climbed from 0.20 to 0.28 mV by augmenting the safflower content in saffron. Therefore, by increasing the level of safflower contamination in saffron, the concentration of eugenol in the IMS rose. The outcomes demonstrated that the selection method effectively detects saffron adulterated with safflower, improving both precision and specificity, and could aid in defining standard quality control procedures for saffron authenticity and quality.

Background and Objectives: Liver fibrosis results from chronic inflammation. Qijia Rougan decoction, a traditional Chinese medicinal formulation, shows hepatoprotective potential, yet its mechanisms remain unclear. This study aims to investigate its antifibrotic effects and underlying mechanisms. Methods: Rat liver fibrosis was induced by carbon tetrachloride (CCl₄) and ethanol exposure. Histopathological assessment was performed using hematoxylin-eosin (HE) and Masson's trichrome staining. Hepatic stellate cell (HSC) activation and autophagic processes were examined through western blot analysis, immunofluorescence staining, and other in vitro assays. Components of Qijia Rougan decoction were analyzed by BATMAN-TCM platform. The pharmacological network was constructed using BATMAN-TCM platform, while disease-related targets were identified through DisGeNET database. Pathway enrichment analysis was conducted using KEGG pathway database. Results: Significant reductions in hepatic index and serum biomarkers (ALT, AST, ALP, TBA, and γ-GT) were observed following Qijia Rougan decoction treatment, with maximal efficacy at 6 weeks. The decoction downregulated of LC3B and α-SMA expression in fibrotic tissues. In vitro, it suppressed LPS-induced α-SMA expression and autophagosome formation in HSC-T6 cells. Network pharmacology analysis of Qijia Rougan decoction identified 274 bioactive compounds and 12,883 potential targets, with pathway analysis indicating PI3K/AKT signaling as the predominant regulatory mechanism. Conclusion: Qijia Rougan decoction alleviates liver fibrosis, potentially by inhibiting HSC activation and autophagy processes via PI3K/AKT/mTOR pathway.

This study investigates the optimal conditions to enrich the phenolic content of the extract from Pandanus amaryllifolius leaves and evaluates the bioactivities of this enrichment. The phenolic enrichment was prepared under optimized conditions using the response surface methodology (RSM) with the Box-Behnken design. The antioxidant properties were assessed using DPPH and hydroxyl radical scavenging assays, while the NO production inhibition was measured in LPS-stimulated RAW 264.7 macrophage cells. Results indicated that the phenolic enrichment showed potent antioxidant activity comparable to ascorbic acid and catechin and significantly higher NO inhibition than the separated nonalkaloid and alkaloid fractions. The study also highlights the synergistic effect of phenolic and alkaloid compounds on the antioxidants and anti-inflammatory activities of the phenolic enrichment from Pandanus amaryllifolius leaves.

The Feng-Liao-Chang-Wei-Kang (FLCWK) capsule is a nationally protected Chinese patent medicine for the treatment of colitis. However, the potential active components and the pharmacological mechanism underlying the anticolitis effect of the FLCWK capsule remain unclear. This study aimed to reveal the active ingredients and possible anticolitis mechanism of the FLCWK capsule using an integrated approach combining mass spectrometry and network pharmacology analysis. Ultra-performance liquid chromatography plus Q-Exactive Orbitrap tandem mass spectrometry (UPLC-Q-Exactive Orbitrap MS) was applied to identify the components of the FLCWK capsule. A network pharmacology study, including target gene prediction and functional enrichment, was applied to screen the active ingredients of the FLCWK capsule and explore its potential mechanism for the treatment of colitis. A total of 115 components were identified in the FLCWK capsule. Network pharmacology results showed that 46 of these compounds with good bioavailability and drug-likeness, such as 4',5-dihydroxyflavone, pinostrobin, naringenin chalcone, apigenin, and morin, were selected as active ingredients. The active ingredients may act on 352 core protein targets, including EGFR, AKT1, PIK3R1, PIK3CB, and MAPK1, thereby modulating relevant pathways, such as MAPK and PI3K-Akt signaling pathways, and thus alleviating inflammation and intestinal damage in colitis. This study provided a useful approach to identify active components and the anticolitis mechanism of the FLCWK capsule and built up a reliable foundation for its clinical treatment.

Background: Hirudin is a major active ingredient of the traditional Chinese medicine leech. It has been proved to have good antithrombotic and anticoagulant effects. Objective: To determine the tissue distribution of hirudin and its pharmacokinetics in vivo by ultrahigh performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). Methods: A total of 21 SPF adult New Zealand rabbits were acclimatized for 1 week, and one was randomly selected as a blank control, while the remaining 18 were randomized to the control group and the model group. The heart, liver, spleen, lung, kidney, brain, plasma, blood vessels, and colon tissues were taken by execution at 1, 3, and 6 h. The samples were assayed using the natural hirudin standard as an external standard. Results: The established UPLC-MS/MS method with good precision, accuracy, recovery, and stability of hirudin proved to be reliable. The correlation between different concentrations of natural hirudin standard and the response value was R ² ≥ 0.9997. The results of the distribution of various tissues showed that hirudin in the two groups had the highest content in plasma and blood vessels, followed by spleen, lung, and liver tissues, and was weaker in the brain and the heart, and the content of hirudin in the control group was higher than that of the model group, and the difference was statistically significant. Conclusion: The absorption and metabolism of hirudin in rabbits with carotid artery injury mainly acted through vascular tissues and blood, and normal rabbits mainly metabolized it through spleen, lung, and liver.

Pharyngiyan tablet is a traditional Chinese medicine (TCM) renowned for its efficacy in moisturizing the lungs, clearing the throat. However, it exhibits quality variations due to discrepancies in regulatory standards and challenges in comprehensive evaluation. In this study, ultra-performance liquid chromatography-quadrupole time-of-flight tandem mass spectrometry (UPLC-Q-TOF-MS/MS) was used to qualitatively analyze the chemical composition of pharyngiyan tablets. Full composition analysis detected 131 chemical constituents. Gallic acid, paeoniflorin, rutin, baicalin, and harpagoside were identified as quality control (QC) indexes through rational screening. These indexes were selected based on their effectiveness in demonstrating differences, stability after processing, specificity, and cost-effectiveness in measurement. For the multimetric quality assessment of the five screening components, a high-performance liquid chromatography with diode array detector (HPLC-DAD) method with wavelength switching was developed. A total of 104 batches of samples from 10 manufacturers were included in the analyses. The content of each ingredient varied significantly across enterprises and batches, with certain enterprises characterized by inferior drug feeding, deviation from prescribed ingredient amounts, and nonstandardized feeding practices. Overall, aquality assessment method was established to provide a basis for the market regulation and quality assessment of pharyngiyan tablets.

A reversed-phase high-performance liquid chromatography (RP-HPLC) method was developed for simultaneous determination of triclabendazole (TCB) and ivermectin (IVM) in pharmaceutical dosage form. A mobile phase consisting of acetonitrile/water (50:50 v/v) with a flow rate of 1.5 mL/min was used for chromatographic separation of the mixture of TCB and IVM. The developed method was found to be linear with the correlation coefficient (r = 0.999) for TCB and IVM in the presence of suspension. The limit of quantitation (LOQ), robustness, specificity, accuracy, and precision were validated for the developed method. The peak areas of five replicates of the samples were recorded, and the acceptance rate of suspension recovery was 98%. The intraday accuracies for TCB and IVM were 98.71% and 100.79%, respectively, with a relative standard deviation (RSD) of 0.87%. The limits of detection (LOD) of TCB and IVM were 0.058 mg/mL and 0.112 μg/mL, respectively, while the LOQ of TCB and IVM were 0.178 μg/mL and 0.340 μg/mL, respectively. The method's % RSD for intra- and interday precision was deemed satisfactory. The developed method could be utilized for the determination and measurement of TCB and IVM in other samples.