New Report of Cyanobacteria and Cyanotoxins in El Pañe Reservoir: A Threat for Water Quality in High-Andean Sources from PERU.

Cyanobacteria are cosmopolitan organisms; nonetheless, climate change and eutrophication are increasing the occurrence of cyanobacteria blooms (cyanoblooms), thereby raising the risk of cyanotoxins in water sources used for drinking, agriculture, and livestock. This study aimed to determine the presence of cyanobacteria, including toxigenic cyanobacteria and the occurrence of cyanotoxins in the El Pañe reservoir located in the high-Andean region, Arequipa, Peru, to support water quality management. The study included morphological observation of cyanobacteria, molecular determination of cyanobacteria (16S rRNA analysis), and analysis of cyanotoxins encoding genes (mcyA for microcystins, cyrJ for cylindrospermopsins, sxtl for saxitoxins, and AnaC for anatoxins). In parallel, chemical analysis using Liquid Chromatography coupled with Mass Spectrometry (LC-MS/MS) was performed to detect the presence of cyanotoxins (microcystins, cylindrospermopsin, saxitoxin, and anatoxin, among others) and quantification of Microcystin-LR. Morphological data show the presence of Dolichospermum sp., which was confirmed by molecular analysis. Microcystis sp. was also detected through 16S rRNA analysis and the presence of mcyA gene related to microcystin production was found in both cyanobacteria. Furthermore, microcystin-LR and demethylated microcystin-LR were identified by chemical analysis. The highest concentrations of microcystin-LR were 40.60 and 25.18 µg/L, in May and November 2022, respectively. Microcystins were detected in cyanobacteria biomass. In contrast, toxins in water (dissolved) were not detected. Microcystin concentrations exceeded many times the values established in Peruvian regulation and the World Health Organization (WHO) in water intended for human consumption (1 µg/L). This first comprehensive report integrates morphological, molecular, and chemical data and confirms the presence of two toxigenic cyanobacteria and the presence of microcystins in El Pañe reservoir. This work points out the need to implement continuous monitoring of cyanobacteria and cyanotoxins in the reservoir and effective water management measures to protect the human population from exposure to these contaminants.

UPLC-MS/MS method for fluconazole determination in plasma and its application in Mexican patients with candidaemia.

Aim: An accurate and fast ultra-high performance liquid chromatography coupled with tandem mass spectrometry analytical method was developed and validated for quantifying fluconazole levels in human plasma according to the US FDA guidelines.Materials & methods: A simple protein precipitation by acetonitrile was employed for the sample preparation. The chromatographic separation was carried out using isocratic elution of water (0.1% formic acid) and acetonitrile on an Acquity ultra-high performance liquid chromatography HSS T3 column. Samples from ten adult patients diagnosed with candidemia who received fluconazole treatment were analyzed.Results & conclusion: The method demonstrated excellent linearity and stability within the 1-50 µg/ml range (r2 >0.999). The intraday and interday precision were determined with coefficient of variation values ranging from 1.4 to 4.38% and 2.8 to 6.6%, respectively. This rapid and selective method has successfully analyzed 27 plasma samples. The straightforward sample preparation in a single step and the reduced analysis time make this method suitable for adult patients with candidemia, leading to improved clinical outcomes.

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Phytochemical, spectroscopic analysis and antifungal activity on bell peppers of hydrothermal bioactive metabolites of Humulus lupulus L. extracts.

This study aimed to evaluate the impact of temperature on the potential extraction of bioactive compounds from aqueous hop extract samples. The main bioactive components were characterised and analysed by LC-MS/MS, FT-IR, phenolic compounds and total flavonoids. Antifungal activity was evaluated in vitro and in vivo in bell peppers. LC-MS/MS analysis demonstrated increases and decreases of bioactive compounds in both extracts depending on the extraction temperature of 25 or 65 °C. The bioactive compounds showed significant changes in the bands between 2786 to 3600 cm-1 and 1022 to 1729 cm-1 in the FT-IR spectrum. The highest antifungal activity against the microorganisms was observed in the EkuanotMT extract at an extraction temperature of 65 °C. The in vivo test with bell peppers presented antifungal activity during five days of evaluation under normal environmental conditions without refrigeration, presenting ≤ 52% of the disease due to F. oxysporum and A. solani.

Comparison of vancomycin assays in patients undergoing hemodialysis.

Vancomycin is a glycopeptide antibiotic mainly excreted by glomerular filtration. Therefore, patients undergoing hemodialysis tend to accumulate its crystalline degradation product, which has been associated with cross-reaction in commercial immunoassays. The aim of this study was to assess the performance of two commercial immunoassays for measuring vancomycin levels in patients undergoing hemodialysis. This method-comparison study enrolled patients undergoing hemodialysis at two hospitals in Porto Alegre, Brazil. Vancomycin serum concentrations measured by Chemiluminescent Microparticle Assay (CMIA) and measured by Kinetic Interaction of Microparticles in Solution (KIMS) were compared with Liquid Chromatography coupled with Tandem Mass Spectrometry (LC-MS/MS). A total of 64 samples from 42 patients and 54 samples from 23 patients were included in CMIA and KIMS groups. Both measurements were highly correlated with LC-MS/MS, with Spearman rank correlation coefficient r = 0.840 (p < 0.001) and r = 0.926 (p < 0.001), respectively. No deviation of linearity was observed (p = 0.81 and p = 0.49, respectively). The mean difference between CMIA and LC-MS/MS was -1.19 µg/mL and between KIMS and LC-MS/MS was -2.28 µg/mL. LC-MS/MS measured levels were, on average, 2.64 % higher than CMIA and 8.81 % higher than KIMS. CMIA and KIMS revealed accurate commercial methods to measure vancomycin serum concentrations in patients undergoing hemodialysis.

Determination of drugs of abuse and metabolites in plasma microsamples by LC-MS/MS after microQuEChERS extraction.

Aim: Identifying drugs of abuse and their metabolites in plasma is vital in both forensic and clinical toxicology. While the QuEChERS (Quick, Easy, Cheap, Effective, Rugged and Safe) method offers an efficient approach to sample preparation, its application is complex due to the wide-ranging properties of target analytes and the challenges posed by biological matrix interferences. This study aims to develop a microQuEChERS approach for the quantification of 14 drugs of abuse and metabolites utilizing minimal sample and solvent volumes.Methods: The microQuEChERS method involved using 10 µl plasma samples, 25 mg of a salt mixture and 150 µl of acetonitrile. Extracts were analyzed by liquid chromatography-tandem mass spectrometry (LC-MS/MS), with a 7.5 min run. The assay was validated according to bioanalytical guidelines.Results: The accuracy was 96.8-112.4%. The within-assay precision was within 2.0-8.9% and the between-assay precision was within 3.2-8.2%. Matrix effects were found to range from -5.7 to 13.5%. The extraction yield was higher than 74.7%.Conclusion: This study described a microQuEChERS sample preparation approach for determining drugs of abuse and metabolites using plasma microsamples and LC-MS/MS. The approach is efficient, environmentally friendly and suitable for scenarios with limited amounts of biological samples.

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Basal release and relaxation responses to 6-nitrodopamine in swine carotid, coronary, femoral, and renal arteries.

Mammalian and reptilian vascular tissues present basal release of 6-nitrodopamine, which is reduced when the tissues are pre-incubated with the NO synthase inhibitor L-NG-Nitro arginine methyl ester (L-NAME), or when the endothelium is mechanically removed. 6-Nitrodopamine induces vasorelaxation in pre-contracted vascular rings by antagonizing the dopaminergic D2-like receptor. Here it was investigated whether male swine vessels (including carotid, left descendent coronary, renal, and femoral arteries) release 6-nitrodopamine, dopamine, noradrenaline, and adrenaline, as measured by liquid chromatography coupled to tandem mass spectrometry. The in vitro vasorelaxant action of 6-nitrodopamine was evaluated in carotid, coronary, renal, and femoral arteries precontracted by U-46619 (3 nM), and compared to that induced by the dopamine D2-receptor antagonist L-741,626. Expression of tyrosine hydroxylase and the neuromaker calretinin was investigated by immunohistochemistry. All vascular tissues presented basal release of endothelium-derived catecholamines. The relaxation induced by 6-nitrodopamine was not affected by preincubation of the tissues with either L-NAME (100 µM, 30-min preincubation) or the heme-site inhibitor of soluble guanylyl cyclase ODQ (100 µM, 30-min preincubation). Electrical field stimulation (EFS)-induced contractions were significantly potentiated by previous incubation with L-NAME, but unaffected by ODQ preincubation. The contractions induced by EFS were reduced by preincubation with either 6-nitrodopamine or L-741,626. Immunohistochemistry in all arteries revealed the presence of tyrosine hydroxylase in the endothelium, whereas immunoreactivity for calretinin was negative. Swine vessels present basal release of endothelium-derived catecholamines and expression of tyrosine hydroxylase in the endothelium. The vasodilation induced by 6-nitrodopamine is due to blockade of dopaminergic D2-like receptors.

Cytotoxic Activity of Lepidium virginicum L. Methanolic Extract on Human Colorectal Cancer Cells, Caco-2, through p53-Mediated Apoptosis.

Colorectal cancer (CRC) is the third most common type of cancer worldwide. Its treatment options have had a limited impact on cancer remission prognosis. Therefore, there is an ongoing need to discover novel anti-cancer agents. Medicinal plants have gained recognition as a source of anti-cancer bioactive compounds. Recently, ethanolic extract of L. virginicum stems ameliorated dinitrobenzene sulfonic acid (DNBS)-induced colitis by modulating the intestinal immune response. However, no scientific study has demonstrated this potential cytotoxic impact on colon cancer cells. The objective of this study was to evaluate the cytotoxic effect of the methanolic extract of L. virginicum (ELv) on a human colorectal adenocarcinoma cell line (Caco-2) and to identify and quantify the phenolic compounds present in ELv extracts by liquid chromatography-mass spectrometry analysis. The cytotoxic activity was assessed using cell viability assays by reduction in the compound 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and lactate dehydrogenase (LDH). MTT and LDH assays revealed that the ELv decreases cell viability in the Caco-2 cell line in a concentration-dependent manner. Cell death was a result of DNA fragmentation and p53-mediated apoptosis. Eight phenolic acids and five flavonoids were identified and quantified in the stems. In conclusion, our findings demonstrate that the extract of L. virginicum possesses cytotoxic properties on Caco-2 cell line, suggesting that it could be a potential source of new drugs against CRC.

Characterizing lipid constituents of B. moojeni snake venom: a comparative approach for chemical and biological investigations.

Snake venoms are complex mixtures majorly composed of proteins with well-studied biological effects. However, the exploration of non-protein components, especially lipids, remains limited despite their potential for discovering bioactive molecules. This study compares three liquid-liquid lipid extraction methods for both chemical and biological analyses of Bothrops moojeni snake venom. The methods evaluated include the Bligh and Dyer method (methanol, chloroform, water), considered standard; the Acunha method, a modification of the Bligh and Dyer protocol; and the Matyash method (MTBE/methanol/water), featuring an organic phase less dense than the aqueous phase. Lipidomic analysis using liquid chromatography with high-resolution mass spectrometry (LC-HRMS) system revealed comparable values of lipid constituents' peak intensity across different extraction methods. Our results show that all methods effectively extracted a similar quantity of lipid species, yielding approximately 17-18 subclasses per method. However, the Matyash and Acunha methods exhibited notably higher proportions of biologically active lipids compared to the Bligh and Dyer method, particularly in extracting lipid species crucial for cellular structure and function, such as sphingomyelins and phosphatidylinositol-phosphate. In conclusion, when selecting a lipid extraction method, it is essential to consider the study's objectives. For a biological approach, it is crucial to evaluate not only the total quantity of extracted lipids but also their quality and biological activity. The Matyash and Acunha methods show promise in this regard, potentially offering a superior option for extracting biologically active lipids compared to the Bligh and Dyer method.

A miniaturized QuEChERS and UPLC-MS/MS method for the determination of mycotoxins in cashew nuts.

This study aimed to develop and validate a multi-mycotoxin analysis method applied to cashew nuts by employing a miniaturized QuEChERS method followed by determination by ultra-performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS). Satisfactory recoveries for the concentrations 1, 10 and 30 ng g-1, ranging from 66% (fumonisin B1) to 110% (ochratoxin A) and relative standard deviations lower than 9% (fumonisin B2) were obtained for the target compounds. Limits of quantification ranged from 0.004 ng g-1 (sterigmatocystin) to 0.59 ng g-1 (alternariol). The applicability of the analytical method was verified by analyzing 30 cashew nut samples from the city of Rio de Janeiro, RJ, southeastern Brazil. Aflatoxins M1, G2, G1, B2, B1, ochratoxin A and sterigmatocystin were detected, respectively, in 27%, 10%, 17%, 30%, 30%, 30% and 50% of the analyzed samples, at maximum concentrations of 0.56, 0.67, 1.43, 2.02, 4.93, 4.81, and 0.35 ng g-1. The maximum limit established by Brazilian legislation for aflatoxins was not exceeded by any of the analyzed samples.

Determination of pesticide residues in urine by chromatography-mass spectrometry: methods and applications.

Introduction: Pollution has emerged as a significant threat to humanity, necessitating a thorough evaluation of its impacts. As a result, various methods for human biomonitoring have been proposed as vital tools for assessing, managing, and mitigating exposure risks. Among these methods, urine stands out as the most commonly analyzed biological sample and the primary matrix for biomonitoring studies. Objectives: This review concentrates on exploring the literature concerning residual pesticide determination in urine, utilizing liquid and gas chromatography coupled with mass spectrometry, and its practical applications. Method: The examination focused on methods developed since 2010. Additionally, applications reported between 2015 and 2022 were thoroughly reviewed, utilizing Web of Science as a primary resource. Synthesis: Recent advancements in chromatography-mass spectrometry technology have significantly enhanced the development of multi-residue methods. These determinations are now capable of simultaneously detecting numerous pesticide residues from various chemical and use classes. Furthermore, these methods encompass analytes from a variety of environmental contaminants, offering a comprehensive approach to biomonitoring. These methodologies have been employed across diverse perspectives, including toxicological studies, assessing pesticide exposure in the general population, occupational exposure among farmers, pest control workers, horticulturists, and florists, as well as investigating consequences during pregnancy and childhood, neurodevelopmental impacts, and reproductive disorders. Future directions: Such strategies were essential in examining the health risks associated with exposure to complex mixtures, including pesticides and other relevant compounds, thereby painting a broader and more accurate picture of human exposure. Moreover, the implementation of integrated strategies, involving international research initiatives and biomonitoring programs, is crucial to optimize resource utilization, enhancing efficiency in health risk assessment.

Determination of high-intensity sweeteners in bakery products marketed in Brazil and dietary exposure assessment.

Bakery products, including biscuits, cakes and breads, generally present a high content of simple sugars of rapid absorption, high fat content and low amount of dietary fiber, which make them highly caloric foods. Although sucrose is a very important ingredient in bakery products for its preservation characteristics and a significant source of energy, there is a growing interest in replacing this sugar with alternative substances, such as high-intensity sweeteners (HIS) that provide sweetness with no or low calories. In Brazil, there is no data on the use of HIS in this class of food. Therefore, the objective of this study was to evaluate the presence of HIS in baked food commercially available in the country and estimate the dietary exposure to these food additives. For that, an analytical method was established for the simultaneous determination of nine HIS in bakery products using ultra-high performance liquid chromatography coupled to tandem mass spectrometry (UHPLC-MS/MS). Sample preparation steps were required based on mechanical kneading for homogenization, hexane extraction of fats, dilution in mobile phase and vortex homogenization, prior to injection into the system. The results obtained during validation showed that coefficients of variation (CV%) for precision were lower than 13.8% and the accuracy was between 91.6% and 109.1%. Aspartame, acesulfame potassium, sodium cyclamate, saccharin, sucralose and steviol glycosides were found in the samples, used alone or in combinations of up five substances. Steviol glycosides were the most found HIS in biscuit samples, while sucralose was the most common sweetener in cake and bread samples. Analysis of product labels revealed only three different claims, .i.e. 'no sugar', 'no added sugar' and 'zero sugar', with the latter being found in 70% of the samples. Exposure to HIS through the consumption of bakery products estimated per eating occasion showed no concerns regarding toxicological risk.

Analysis of the UV filter Benzophenone-3 assimilation in Crossostrea gigas oysters post-exposure in a controlled environment by LC-MS/MS.

Benzophenone-3 (BP-3), utilized as a UV filter in cosmetic products, is an emerging contaminant that constitutes a threat to natural resources and environmental health. This study investigated the assimilation of the UV filter BP-3 in Crassostrea gigas oysters collected in Florianópolis, Santa Catarina, Brazil. Lyophilized oyster tissue extracts were prepared using the QuEChERS method, and LC-MS/MS was employed to determine the BP-3 concentration in the samples. The method was applied to specimens intentionally exposed to two concentrations of the contaminant, for different periods of exposure (1 and 7 days). Samples from treatment 1 (T1) were exposed to a concentration of 1 µg L-1 of the BP-3 standard, and samples from treatment 2 (T2) were exposed to a concentration of 100 µg L-1 of the BP-3 standard. The results revealed rapid absorption of BP-3, with an increase of 126% for lower concentrations, reaching 1.13 µg of BP-3 per gram of oyster tissue, and 17% for higher concentrations, reaching 34.6 µg of BP-3 per gram of oyster tissue after 7 days. The presence of BP-3 even in samples not directly exposed to the contaminant indicates its widespread environmental distribution. The rapid bioaccumulation suggests the need to consider seasonal variations, such as increased tourism in the summer. The validated analytical method demonstrated efficacy in quantifying BP-3, providing an integrated approach for long-term monitoring of pollution levels and their dynamic variations over time. In addition, variation in BP-3 levels in the samples may be related to transport patterns influenced by tides and discharges from septic system, highlighting the need to improve wastewater treatment. These findings underscore the necessity for continuous biomonitoring and effective environmental management to safeguard the health of marine ecosystems and humans.

Dereplication of 4-Quinolone Alkaloids from Waltheria Indica (Malvaceae) Tissues Using Molecular Network Tools.

Waltheria indica (Malvaceae) is a plant popularly used in folk medicine by traditional African and indigenous communities, and in various countries worldwide, to treat general inflammation. Several biological activities of this plant have been reported, including acetylcholinesterase inhibition and potential anti-human immunodeficiency virus (HIV), antinociceptive, analgesic, antifungal, anticancer, anti-inflammatory, leishmanicidal, trypanocidal, antioxidant, and antibacterial activities. The chemical profile of Waltheria indica was assessed by dereplication analysis using UPLC-MS/MS, and data acquisition was performed using chemoinformatics tools, such as Mass Spectrometry-Data Independent AnaLysis (MS-DIAL) and MS-FINDER softwares. The preprocessed data were sent to the GNPS to build a feature-based molecular network (FBMN). Thirty-three 4-quinolone alkaloids were annotated in the extracts and fractions of stems and roots, whereas 12 were annotated in the extracts and fractions of flowers and leaves. This represents an inaugural chemical investigation study employing UPLC-Q-TOF-MS/MS analysis, along with a molecular network approach, within this species and genus.

Comprehensive analysis of contaminants in Brazilian infant formulas: Application of QuEChERS coupled with UHPLC-QqQ-MS/MS and suspect screening-unknown analysis by UHPLC-Q-Orbitrap-MS.

Infant formulas (IF) can contain harmful chemical substances, such as pesticides and mycotoxins, resulting from the contamination of raw materials and inputs used in the production chain, which can cause adverse effects to infants. Therefore, the quick, easy, cheap, effective, rugged, and safe (QuEChERS) methodology prior ultra-high performance liquid chromatography coupled to triple quadrupole mass spectrometry (UHPL-QqQ-MS/MS) analysis was applied for the determination of 23 contaminants, in 30 samples of Brazilian IF. The method was validated in terms of limit of detection (0.2 to 0.4 µg/kg), limits of quantification (1 and 10 µg/kg), and recovery (64 % to 122 %); precision values, in terms of relative standard deviation (RSD), were ≤ 20 %. Fenitrothion, chlorpyrifos, and bifenthrin were the pesticides detected in the samples, but the values did not exceed the limit set by the European Union (EU), and ANVISA, and they were detected under their limits of quantification. Additionally, suspect screening and unknown analysis were conducted to tentatively identify 32 substances, including some compounds not covered in this study, such as pesticides, hormones, and veterinary drugs. Carbofuran was identified, confirmed and quantified in 10 % of the samples.

New records on toxic cyanobacteria from Brazil: Exploring their occurrence and geography.

Cyanobacterial Harmful Algal Blooms (CyanoHABs) pose a significant threat to communities globally, impacting ecosystems and public health. This study provides an in-depth review of the current state of cyanotoxins and the distribution of CyanoHABs species in Brazil, while also detailing the methods used for their detection. Four hundred and twenty-one incidents were analyzed from 1993 to 2021, compiling cyanotoxin records and toxic CyanoHABs occurrences. The investigation begins with the first detection of microcystins in 1994 and highlights pivotal moments, like the 1996 "Caruaru Syndrome" outbreak. This event encouraged research and updated cyanotoxin-monitoring guidelines. The Brazilian drought period of 2015-2016 exacerbated cyanobacterial growth and saxitoxin levels, coinciding with Zika-related microcephaly. This study delves into methods used for cyanotoxin analysis, including ELISA, bioassays, HPLC, and LC-MS. Additionally, we investigated the toxicity of 37 cyanobacterial strains isolated from various Brazilian environments. Extracts were tested against Artemia salina and analyzed by LC-MS. Results revealed toxicity in extracts from 49 % of cyanobacterial strains. LC-MS results were analyzed using GNPS MS/MS molecular networking for comparing experimental spectra with those of cyanotoxin standards against in-house databases and the existing literature. Our research underscores the variability in cyanotoxin production among species and over time, extending beyond microcystins. LC-MS results, interpreted through the GNPS platform, revealed six cyanotoxin groups in Brazilian strains. Yet, compounds present in 75 % of the toxic extracts remained unidentified. Further research is crucial for fully comprehending the impact of potentially harmful organisms on water quality and public health management strategies. The study highlights the urgent need for continuously monitoring cyanobacteria and the cyanotoxin inclusion of management in public health policies.

A LC-MS/MS method for the simultaneous determination of 6-cyanodopamine, 6-nitrodopamine, 6-nitrodopa, 6-nitroadrenaline and 6-bromodopamine in human plasma and its clinical application in patients with chronic kidney disease.

The aim of this study was to develop a high-performance liquid chromatography-tandem mass spectrometry method for the determination of 6-cyanodopamine, 6-nitrodopamine, 6-nitrodopa, 6-nitroadrenaline and 6-bromodopamine in human plasma samples. Strata-X 33 µm solid-phase extraction cartridges were used for the extraction of the catecholamines from human plasma samples. The catecholamines were separated in a 150 × 3 mm Shim-pack GIST C18-AQ column with 3 µm particle size, placed in an oven at 40°C and perfused with 82% mobile phase A (acetonitrile-H2O; 90:10, v/v) + 0.4% acetic acid and 18% mobile phase B (deionized H2O) + 0.2% formic acid at a flow rate of 340 µl/min in isocratic mode. The injected volume was 4 µl and the run lasted 4 min. The method was linear from 0.1 to 20 ng/ml and the lower limit of quantification was 0.1 ng/ml for all analytes. The method was applied to evaluate the plasma levels of catecholamines in plasma of patients with chronic kidney disease and allowed the detection for the first time of circulating levels of the novel catecholamines 6-bromodopamine and 6-cyanodopamine.

Ecotoxicological strategies employing biochemical markers and organisms to monitor the efficacy of malathion photolysis treatment.

The objective of this study was to assess the photolysis-mediated degradation of malathion in standard and commercial formulations, and to determine the toxicity of these degraded formulations. Degradation tests were carried out with 500 µg L-1 of malathion and repeated three times. The initial and residual toxicity was assessed by using Lactuca sativa seeds for phytotoxicity, Stegomyia aegypti larvae for acute toxicity, and Stegomyia aegypti mosquitoes (cultivated from the larval stage until emergence as mosquitoes) to evaluate the biochemical markers of sublethal concentrations. For the standard formulations the photolytic process efficiently reduced the initial concentration of malathion to levels below the regulatory limits however, the formation of byproducts was revealed by chromatography, which allowed for a more complete proposal of photolytic-mediated malathion degradation route. The degraded formulations inhibited the growth of L. sativa seeds, while only the untreated formulations showed larvicidal activity and mortality. Both formulations slightly inhibited acetylcholinesterase activity in S. aegypti mosquitoes, while the standard formulation decreased and the commercial formulation increased glutathione S-transferase activity. However, there were no significant differences for superoxide dismutase, esterase-α, esterase-ß and lipid peroxidation. These findings indicate that in the absence of the target compound, the presence of byproducts can alter the enzymatic activity. In general, photolysis effectively degrade malathion lower than the legislation values; however, longer treatment times must be evaluated for the commercial formulation.

Development of an innovative analytical method for forensic detection of cocaine, antidepressants, and metabolites in postmortem blood using magnetic nanoparticles.

Cocaine and antidepressants rank high globally in substance consumption, emphasizing their impact on public health. The determination of these compounds and related substances in biological samples is crucial for forensic toxicology. This study focused on developing an innovative analytical method for the determination of cocaine, antidepressants, and their related metabolites in postmortem blood samples, using unmodified commercial Fe3O4 nanoparticles as a sorbent for dispersive magnetic solid-phase extraction (m-d-SPE), coupled with liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) analysis. An aliquot of 100 µL of whole blood and 5 µL of the internal standard pool were added to 30 mg of nanoparticles. The nanoparticles were separated from the sample using a neodymium magnet inserted into a 3D-printed microtube rack. The liquid was then discarded, followed by desorption with 300 µL of 1/1/1 acetonitrile/methanol/ethyl acetate. The sample was vortexed and separated, and 1.5 µL of the organic supernatant was injected into the LC-MS/MS. The method was acceptably validated and successfully applied to 263 postmortem blood samples. All samples evaluated in this study were positive for at least one substance. The most frequent analyte was benzoylecgonine, followed by cocaine and cocaethylene. The most common antidepressants encountered in the analyzed samples were citalopram and fluoxetine, followed by fluoxetine's metabolite norfluoxetine. This study describes the first report of this sorbent in postmortem blood analysis, demonstrating satisfactory results for linearity, precision, accuracy, and selectivity for all compounds. The method's applicability was confirmed, establishing it as an efficient and sustainable alternative to traditional techniques for forensic casework.

Behavior of diclofenac from contaminated fish after cooking and in vitro digestion.

BACKGROUND: Seafood consumers are widely exposed to diclofenac due to the high contamination levels often present in aquatic organisms. It is a potential risk to public health due its endocrine disruptor properties. Limited information is available about diclofenac behavior after food digestion to enable a more realistic scenario of consumer exposure. This study aimed to evaluate cooking effects on diclofenac levels, and determine diclofenac bioaccessibility by an in vitro digestion assay, using commercial fish species (seabass and white mullet) as models. The production of the main metabolite 4'-hydroxydiclofenac was also investigated. Fish hamburgers were spiked at two levels (150 and 1000 ng g-1) and submitted to three culinary treatments (roasting, steaming and grilling). RESULTS: The loss of water seems to increase the diclofenac levels after cooking, except in seabass with higher levels. The high bioaccessibility of diclofenac (59.1-98.3%) observed in both fish species indicates that consumers' intestines are more susceptible to absorption, which can be worrisome depending on the level of contamination. Contamination levels did not affect the diclofenac bioaccessibility in both species. Seabass, the fattest species, exhibited a higher bioaccessibility of diclofenac compared to white mullet. Overall, cooking decreased diclofenac bioaccessibility by up to 40% in seabass and 25% in white mullet. The main metabolite 4'-hydroxydiclofenac was not detected after cooking or digestion. CONCLUSION: Thus, consumption of cooked fish, preferentially grilled seabass and steamed or baked white mullet are more advisable. This study highlights the importance to consider bioaccessibility and cooking in hazard characterization studies. © 2024 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Determination of meropenem in capillary plasma microsamples using LC-MS/MS.

Background: The measurement of meropenem plasma concentrations is employed for dosing regimen individualization. The aim of this study was to develop and validate a LC-MS/MS assay for quantification of meropenem in capillary plasma microsamples. Methods: Samples were prepared by protein precipitation with acetonitrile, followed by clean-up with dichloromethane. The method was validated and applied to 12 paired samples of venous and capillary plasma. Results: The method was linear in the range of 0.5-50 µg/ml. Matrix effects were minimal. Inter- and intra-assay were 3.8-7.9% and 2.7-5.5%, respectively, while accuracy was 91.7-100.6%. Concentrations in capillary and venous plasma were highly correlated. Conclusion: An assay for the quantification of meropenem in capillary plasma microsamples was fully validated, showing potential for clinical application.

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