RESUMO
Alcohol biomarkers are able to reflect the degree of recent or long-term alcohol consumption, covering different windows of detection. Phosphatidylethanols (PEths) are an emerging group of direct alcohol biomarkers that are widely applied in clinical and forensic applications. Their quantification can provide insight into an individual's drinking behaviour. Here, we present a new sub-class of yet unknown PEth species, LysoPEths, which are structurally related to PEth, but miss one fatty acyl chain. LysoPEths can be either a degradation product of PEth or a product of transesterification of lyso-phosphatidylcholine (LysoPC) with ethanol. To set up an analytical method, LysoPEth 16:0 was synthesised from PC 16:0/18:1 and characterised by LC-MS/MS, using an enzymatic method: phospholipase D (PLD), followed by phospholipase A2 (PLA2). Then, an LC-MS/MS method in MRM mode for LysoPEth 16:0 with additional LysoPEth species (LysoPEth 18:1, LysoPEth 18:2, and LysoPEth 20:4) and PEth 16:0/20:4 was developed. By incubation of freshly sampled venous blood of a teetotaller with ethanol at different concentrations, the formation of LysoPEth in parallel to PEth was investigated. With increasing ethanol concentrations, LysoPEth 16:0 was formed besides the known PEth species (PEth 16:0/18:1, PEth 16:0/18:2) for up to 72â h with LysoPEth concentrations being about three times lower than PEth concentrations. Storage of ethanol-free PEth-positive blood of an alcohol consumer at 37 °C showed that LysoPEth 16:0 concentrations increased, while PEth 16:0/18:1 concentrations decreased in the first 24â h for frozen/thawed blood, however not for freshly collected blood. Furthermore, LysoPEth 16:0 was detected in venous as well as lyophilised blood from clinical and forensic case work alongside with PEth 16:0/18:1, 16:0/18:2, and other PEth and LysoPEth species (PEth 16:0/20:4, LysoPEth 18:1, LysoPEth 18:2, and LysoPEth 20:4). LysoPEth 16:0 concentrations were found to be in linear correlation with PEth 16:0/18:1 (r2 = 0.75).
Assuntos
Consumo de Bebidas Alcoólicas , Espectrometria de Massas em Tandem , Cromatografia Líquida , Espectrometria de Massas em Tandem/métodos , Etanol , Lecitinas , BiomarcadoresRESUMO
Vapor intrusion is detrimental for indoor air quality. One of the most common sources of vapor intrusion is soil contaminated with petroleum hydrocarbons. To evaluate the long-term risk from individual exposure to hydrocarbons it is necessary to measure quantitively and reliably an average concentration level of individual pollutants on a monthly or yearly basis. Temporal variability of vapor intrusion from hydrocarbons poses a significant challenge to determination of average exposure and there is a need for reliable long-term integrative sampling. To this end, an analytical method for determination of 10 selected nonmethane hydrocarbons (NMHCs), including hexane, heptane, octane, decane, benzene, toluene, ethyl-benzene, m,p-xylene, o-xylene, and naphthalene, sampled on active triple-bed tubes filled with Carbograph 2, Carbograph 1, and Carboxen 1003 adsorbents was developed and validated. Extensive laboratory studies proved the absence of breakthrough at 50% HR and ambient temperature for experiments lasting up to 28 days and established a safe sampling time/volume of 20 days/114 L when sampling at a low flow rate of around 4 mL min-1. In addition, the developed method includes detailed uncertainty calculations for determination of concentrations. Finally, the method was tested by measuring NMHC concentrations in indoor air at a former industrial site during a 2-month-long field campaign in Lyon. The results of the field campaign suggest that 4-week integrated concentration measurements can be achieved by using active sampling on triple-bed tubes at 4.5 mL min-1.
Assuntos
Poluentes Atmosféricos , Poluição do Ar em Ambientes Fechados , Petróleo , Poluentes Atmosféricos/análise , Poluição do Ar em Ambientes Fechados/análise , Benzeno , Hidrocarbonetos/análise , Petróleo/análise , Gases , Monitoramento Ambiental/métodosRESUMO
The characterisation of cannabis plants, especially the determination of specific phytocannabinoids, has gained enormous importance in the last decade, mainly due to the recent changes in cannabis control in several countries or states. This is particularly relevant for the forensic, medical or recreative industry to have a rapid, inexpensive, and reliable methodology to identify and quantify phytocannabinoids. Furthermore, spiking cannabis products with Δ8-tetrahydrocannabinol (THC) is a contemporary trend that demands improving or replacing current methods to include this cannabinoid. The current study presents an ultrasound-assisted solid-liquid extraction followed by high-performance liquid chromatography with diode array detection (HPLC-DAD) methodology to identify and quantify Δ9-THC, Δ8-THC, cannabidiol, cannabinol, Δ9-tetrahydrocannabinolic acid and cannabidiolic acid in cannabis products. The herbal samples were extracted with ethanol:acetonitrile (50:50, v:v) by ultrasonication using only 50 mg of sample. The plant oils were diluted in ethanol. The optimised procedure allowed ≈100% extraction efficiency of the target cannabinoids. The validation assays showed that the method is linear (R2 > 0.997), selective, sensitive, precise and accurate, with suitable limits of detection (0.125-0.250 µg mL-1) and quantification (0.500 µg mL-1). The method was successfully applied to cannabis samples, demonstrating its suitability for routine analyses. This contribution follows the current demand for fast and straightforward analysis services of this plant and its derivatives, using small amounts of sample. The present study compares very favourably against other works, particularly in regards to the extraction efficiency, speed of the overall procedure, method sensitivity, and ability to monitor Δ8-THC spiked samples using a novel solvent mixture.
Assuntos
Canabidiol , Cannabis , Cannabis/química , Cromatografia Líquida de Alta Pressão/métodos , Dronabinol/análise , Extratos Vegetais/química , Canabinol/análise , Canabidiol/análiseRESUMO
Several cannabinoids (cannabidivarin (CBDV), cannabigerol (CBG), cannabidiol (CBD), cannabinol (CBN) and cannabichromene (CBC)) and ethanol hemp extract are being used in primary human hepatocytes (PHH), Caenorhabditis elegans (C. elegans) and in vitro buccal membrane absorption models to elucidate their potential toxicological mechanisms, evaluate their oromucosal absorption, and to identify their metabolites. William's E medium, C. elegans habitation medium (CeHM), and HEPES-buffered hanks' balanced salt solution (HHBSS) are matrices used with these predictive test systems. Therefore, we developed and validated a sensitive fit-for-purpose ultra-high performance liquid chromatography-electrospray-tandem mass spectrometry (UHPLC-ESI-MS/MS) method for the quantitation of CBDV, CBG, CBD, CBN, and CBC in extracellular matrices used with these models for the first time. The separation of the analytes was performed on a Waters ACQUITY UPLC BEH C18 column (130 Å, 1.7 µm, 2.1 × 100 mm) protected with a Waters ACQUITY UPLC BEH C18 guard column (130 Å, 1.7 µm, 2.1 × 5 mm). Positive electrospray ionization and multiple reaction monitoring (MRM) modes were used. Under the developed experimental conditions, good linearities were obtained over the concentration range of 0.025-40 µg/ml with coefficients of determination (R2) varying from 0.9953 to 0.9998. The intra-day precisions were between 0.5 and 9.6% with accuracies within ± 16.7%, and the inter-day precisions ranged from 0.6 to 13.1 % with accuracies within ± 13.7%. The method recoveries were between 85.8 and 105.1%. In addition, time-consuming sample preparation was avoided by applying a simple and efficient extraction procedure, which meets the need for potential large-scale routine analysis. The described method was successfully applied to quantitate the analytes in samples produced with different models as well as in ethanolic hemp extract.
Assuntos
Canabidiol , Espectrometria de Massas em Tandem , Humanos , Animais , Caenorhabditis elegans , Cromatografia Líquida de Alta Pressão , Canabinol , Etanol , Extratos VegetaisRESUMO
OBJECTIVES: Ethical dilemmas at both the individual and structural level are part of the daily work of midwives and gender inequality and injustice can affect women's sexual and reproductive health. Mainstream bioethical theory has been criticized for neglecting women's issues. To ensure women's experiences are addressed, a gender lens on ethics is crucial. AIM: This study develops a theory model by exploring ethical dilemmas related to gender in the context of maternity care from the perspective of midwifery science and feminist ethics. METHODS: The research strategy followed a coherent stepwise approach: literature search, thematic analysis, elaboration of a gender ethics protocol, and the integration of various components into a preliminary gender ethics model for midwifery. FINDINGS: A literature search was performed using Scopus and Web of Science to identify ethical dilemmas in maternity care linked to gender and power. The search of articles published between 1996 and 2019 returned 61 abstracts. These abstracts were screened and assigned one of the following themes: The Midwifery Profession, The Rights of the Woman, Fetal Rights Dominate, and Medicalization of Pregnancy and Childbirth. A tentative gender ethics frame was developed and tested on two articles on abortion, one from Denmark and one from Japan. The protocol facilitated the gender analysis of ethical dilemmas related to abortion, which were related to the imbalance of power relations in health care. In the final step, we synthesized the dimensions of gender and power in a gender ethics model for midwifery. DISCUSSION: The gender ethics protocol developed revealed gendered dimensions of ethical dilemmas in midwifery. This gender analysis adds to the understanding of the "do no harm" principle by revealing assumptions and stereotypes that promote unequal power relations. The gender ethics model is an innovative approach that envisions and exposes power imbalance at the micro, meso, and macro levels. CONCLUSIONS: The protocol could improve gender competence among researchers, midwives/professionals, and midwifery students throughout the world.
As gender inequity, gender inequality, and oppression infuse dimensions in all human cultures and societies, not the least in midwifery practice where the layers of injustice affect women during pregnancy and birth in high-, middle-, and low-income countries, the time has come to renew the perspectives of normative ethics. In this study, we explore gender ethical dilemmas unique to maternity care from the perspective of midwifery science and feminist ethics. A literature search uncovered ethical dilemmas in midwifery, and four broad themes were identified: Midwifery Profession, Rights of the Woman, Fetal Rights Dominate, and Medicalization of Pregnancy and Childbirth. Next, we developed a gender ethics protocol suitable for providing gender ethical interpretations of results. The protocol was tested and refined using two articles (one from the Denmark and one from Japan) that address ethical dilemmas of abortion care. The pilot analysis indicates that the autonomy of midwives and their scope of practice might be constrained and that the obstetric medicalized/authoritative knowledge still plays a dominate role in maternity practice. Here, we present an elaborate model, gender ethics model for midwifery (GEMM), developed for midwifery science that can be further refined. The model challenges the views of maternity care and contributes to a deeper understanding of how fluid concepts such as gender and power circulate and influence women's and birthing person's sexual and reproductive health.
Assuntos
Serviços de Saúde Materna , Tocologia , Obstetrícia , Feminino , Humanos , Gravidez , Princípios MoraisRESUMO
A new liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed for the analysis of ginsenosides in three Panax ginseng reference materials (RMs). Extraction procedures were optimized to recover neutral and malonyl-ginsenosides using a methanol-water extraction under basic conditions. Optimized mass fragmentation transitions were obtained for the development of a multiple reaction monitoring (MRM) detection method with electrospray ionization in negative and positive ion mode. Mass fraction values were determined for ginsenosides Rb1, Rb2, Rc, Rd, Re, Rf, and Rg1 in the three ginseng materials (rhizomes, extract, and an oral dosage form). Quantitation of these seven compounds was accomplished with 4-methylestradiol and SRM 3389 Ginsenoside Calibration Solution serving as an internal standard (IS) and calibration standards, respectively. Mass fraction values for the seven ginsenosides ranged from 1.27 mg/g to 21.42 mg/g, 3.25 mg/g to 35.81 mg/g, and 0.56 mg/g to 2.51 mg/g for SRM 3384, SRM 3385, and RM 8664, respectively.
Assuntos
Ginsenosídeos , Panax , Panax/química , Ginsenosídeos/análise , Cromatografia Líquida , Espectrometria de Massas em Tandem/métodos , Rizoma/química , Cromatografia Líquida de Alta Pressão/métodosRESUMO
Leaves from Adhatoda vasica Nees, Acanthaceae (synonym Justicia adhatoda L.) have been widely used in traditional medicine for their beneficial effect in the treatment of respiratory diseases. Vasicine, the main quinazoline alkaloid in A. vasica, has been linked to its medicinal properties. The purpose of this work was to develop and validate a reliable analytical method for the quantification of vasicine in A. vasica leaves and commercially available products. For this purpose, a high-performance liquid chromatography method coupled to diode array detection (HPLC-DAD) was used. After optimization of the extraction process and the HPLC conditions, linearity, precision, accuracy, and specificity were checked. During the validation, six commonly available food supplements and dosage forms were tested using the validated method. The calibration model was found to be linear in the concentration range of 5.125-205 µg/mL. The average vasicine content at different concentration levels was 0.99 g/100 g with an RSD% of 0.05%. The average recovery was found to be 102.3% with an RSD of 4.3%. Additionally, it was confirmed that the validated method was still precise and accurate for quantifying vasicine in other matrices like the tested preparations. In summary, the validated method was suitable for the determination of vasicine in leaves of Adhatoda vasica, as well as for investigating the quality and the prescribed intake of several commercial products.
RESUMO
Oncheong-eum (OCE) is a traditional herbal prescription made by combining Samul-tang and Hwangryunhaedok-tang. It is primarily used to treat gynecological disorders such as metrorrhagia and metrostaxis. In the present study, we focused on developing and validating a simultaneous assay for the quality control of OCE using 19 marker components (gallic acid, 5-(hydroxymethyl)furfural, chlorogenic acid, geniposide, coptisine chloride, jatrorrhizine chloride, paeoniflorin, berberine chloride, palmatine chloride, ferulic acid, nodakenin, benzoic acid, baicalin, benzoylpaeoniflorin, wogonoside, baicalein, wogonin, decursin, and decursinol angelate). This analysis was performed using high-performance liquid chromatography coupled with a diode array detector, and chromatographic separation of the 19 markers was carried out using a SunFireTM C18 reversed-phase column and gradient elution conditions with two mobile phases (0.1% aqueous formic acid-0.1% formic acid in acetonitrile). The developed analytical method was validated through linearity, limits of detection and quantification, recovery, and precision. Under this assay, 19 markers in OCE samples were detected at not detected-9.62 mg/g. The analytical methods developed and validated in our research will have value as basic data for the quality control of related traditional herbal prescriptions as well as OCE.
Assuntos
Medicamentos de Ervas Chinesas , Cromatografia Líquida de Alta Pressão/métodos , Medicamentos de Ervas Chinesas/química , Controle de Qualidade , Reprodutibilidade dos TestesRESUMO
The Box-Behnken response surface design together with the individual desirability functions were used to develop the new and greenish sample preparation procedure of coffee brews prior to their multielement (Ba, Ca, Cu, Fe, K, Mg, Mn, Na, Sr and Zn) analysis by inductively coupled plasma optical emission spectrometry (ICP OES). The developed procedure required only 2-fold dilution of the samples with a 1.8 mol L-1 HNO3 solution and then, the sonication of the resulting samples solutions for 8 min at room temperature. The proposed method was precise (0.6-7.5% as RSD), true (relative errors changing from -5.2% to +4.6%) and guaranteed the limits of detection (LODs) of the studied elements between 0.1 and 5 ng g-1. Finally, this simplified ICP OES based method was applied for the multielement analysis of brews of different Arabica coffees as well as those prepared with seldomly reported devices, i.e., dripper, slow dripper, French press, aeropress and syphon.
Assuntos
Café , Oligoelementos , Café/química , Íons , Análise Espectral/métodos , Oligoelementos/análise , Zinco/análiseRESUMO
Protein separation can be achieved with different modes of capillary electrophoresis, such as with capillary gel electroporesis (CGE) or with capillary zone electrophoresis (CZE). CZE protein mapping of peanut extract was approached in four different ways, combining neutral-coated or multilayer-coated capillaries with pHs well over or under the isoelectric point range of the proteins of interest. At acidic pHs, the mobility ranges of the major peanut allergens Ara h1, Ara h2, Ara h3, and Ara h6 were identified. Although the pH is a major factor in CZE separation, buffers with different compositions but with the same pH and ionic strength showed significantly different resolutions. Different components of the electrolyte were studied in a multifactorial design of experiment. CE-SDS and CZE proved to be suitable for protein mapping and we were able to distinguish different batches of peanut extract and burned peanut extract.
Assuntos
Alérgenos , Arachis , Arachis/metabolismo , Eletroforese Capilar/métodos , Extratos Vegetais/metabolismo , Proteínas/metabolismoRESUMO
Abstract The objective of the present study is to develop and validate a simple, selective and accurate hydrophilic interaction liquid chromatography - a high performance liquid chromatography incorporating an evaporative light scattering detector (HILIC-HPLC-ELSD) method for simultaneously determining glucosamine hydrochloride and chondroitin sulfate in dietary supplements. The chromatographic separation was carried out on a ZIC-HILIC column (150 mm x 4.6 mm x 5µm) in isocratic system mode with a mobile phase of acetonitrile, 30 mM ammonium formate and water (77:20:3, v/v/v) at pH 4.5, a column temperature of 35°C, a flow rate of 1 mL.min-1, and an injection volume of 5 µL. An evaporative light scattering (ELS) detector was used. Effective separation was achieved by means of analyte resolution of more than 1.5 with an analysis run time of approximately 20 minutes. The linearity of glucosamine hydrochloride and chondroitin sulfate ranged from 0.4 to 2.5 mg.mL-1. The limits of the detection and quantification of glucosamine hydrochloride were 20 and 80 mg.mL-1 respectively, while for chondroitin sulfate they were 80 and 400 mg.mL-1. All validation parameters satisfied the acceptance criteria in accordance with International Conference on Harmonisation (ICH) guidelines. The method was successfully applied to the assay of commercial dietary supplement samples
Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Cromatografia Líquida/métodos , Suplementos Nutricionais/análise , Estudo de Validação , Glucosamina/agonistasRESUMO
Polianthes tuberosa (Linn.) is traditionally considered an ornamental and medicinal plant worldwide. However, extensive studies on its phytochemical composition are very limited. Hence the present work aims to identify the total phytochemical ingredients present in different crude extracts of tuberosa. Phytochemical analysis has been carried out for differential cold solvent extracts of various parts of tuberosa such as petals, stamens, and ovary by gas chromatography coupled with mass spectrometry, ultra-performance liquid chromatography to quadrupole time-of-flight mass spectrometry, and evaporative light scattering detector analyzers for the identification of bioactive components. Among the various solvents used for the extraction, diethyl ether is found to be the most suitable and efficient solvent, as its total differential recovery from the crude extract is about 0.24% as compared to 0.04% obtained by using n-hexane or petroleum ether. Numerous phytochemicals have been identified by the chromatography and MS techniques, which demonstrate the presence of essential fatty acids along with other pharmacological importance phytoconstituents. Identification of additional phytochemicals present in the crude extract of tuberosa flower further enhances its biological and pharmacological significance. The present work lays a foundation for further research and development of phytoconstituents of the tuberosa flower.
Assuntos
Asparagaceae/química , Compostos Fitoquímicos/análise , Compostos Fitoquímicos/química , Extratos Vegetais/química , Flores/química , Cromatografia Gasosa-Espectrometria de Massas , Espectrofotometria UltravioletaRESUMO
Many international guidance documents for deriving water quality guideline values recommend the use of chronic toxicity data. For the tropical fish northern trout gudgeon, Mogurnda mogurnda, 96-h acute and 28-d chronic toxicity tests have been developed, but both tests have drawbacks. The 96-h toxicity test is acute and has a lethal endpoint; hence it is not a preferred method for guideline value derivation. The 28-d method has a sublethal (growth) endpoint, but is highly resource intensive and is high risk in terms of not meeting quality control criteria. The present study aimed to determine the feasibility of a 7-d larval growth toxicity test as an alternative to the 96-h survival and 28-d growth tests. Once the method was successfully developed, derived toxicity estimates for uranium, magnesium, and manganese were compared with those for other endpoints and tests lengths within the literature. As a final validation of the 7-d method, the sensitivity of the 7-d growth endpoint was compared with those of 14-, 21-, and 28-d exposures. Fish growth rate, based on length, over 7 d was significantly more sensitive compared with existing acute toxicity endpoints for magnesium and manganese, and was similarly sensitive to existing chronic toxicity endpoints for uranium. For uranium, the sensitivity of the growth endpoint over the 4 exposure periods was similar, suggesting that 7 d as an exposure duration is sufficient to provide an indication of longer term chronic growth effects. The sensitivity of the 7-d method, across the 3 metals tested, highlights the benefit of utilizing the highly reliable short-term 7-d chronic toxicity test method in future toxicity testing using M. mogurnda. Environ Toxicol Chem 2021;40:1596-1605. © 2021 Commonwealth of Australia. Environmental Toxicology and Chemistry © 2021 SETAC.
Assuntos
Urânio , Poluentes Químicos da Água , Animais , Magnésio , Manganês/toxicidade , Testes de Toxicidade Crônica , Truta , Urânio/análise , Urânio/toxicidade , Poluentes Químicos da Água/toxicidadeRESUMO
Human hair has been identified as a non-invasive alternative matrix for assessing the human exposure to specific organic contaminants. In the present study, a solvent-saving analytical method for the simultaneous determination of 8 polybrominated diphenyl ethers (PBDEs), 3 hexabromocyclododecanes (HBCDDs), 12 phosphorus flame retardants (PFRs), and 4 emerging PFRs (ePFRs) has been developed and validated for the first time. Hair sample preparation protocols include precleaning with Milli-Q water, digestion with HNO3/H2O2 (1:1, v/v), liquid-liquid extraction with hexane:dichloromethane (4:1, v/v), and fractionation and cleanup on a Florisil cartridge. The method was validated by using two levels of spiked hair samples of 3 replicates for each spiking group. Limits of quantification (LOQs) were 0.12-22.4 ng/g for all analytes, average values of accuracies were ranging between 88 and 115%, 82-117%, 81-128%, and 81-95% for PBDEs, HBCDDs, PFRs, and ePFRs, respectively; and precision was also acceptable (RSD < 20%) for all analytes. Eventually, this method was applied to measure the levels of the targeted analytes in hair samples of e-waste dismantling workers (n = 14) from Qingyuan, South China. Median values ranged between 3.00 and 18.1 ng/g for PBDEs, 0.84-4.04 ng/g for HBCDDs, 2.13-131 ng/g PFRs, and 1.49-29.4 ng/g for ePFRs, respectively. PFRs/ePFRs constitute the major compounds in human hair samples, implying the wide use of PFRs/ePFRs as replacements of PBDEs and HBCDDs, as well the potential high human exposure risks of PFRs/ePFRs. Overall, this work will allow to a comprehensive assessment of human exposure to multiple groups of FRs using hair as a non-invasive bioindicator.
Assuntos
Retardadores de Chama/análise , Cabelo/química , Éteres Difenil Halogenados/análise , Hidrocarbonetos Bromados/análise , China , Monitoramento Ambiental/métodos , Humanos , Peróxido de Hidrogênio/análise , Extração Líquido-Líquido , Fósforo/análiseRESUMO
Aim: Vitamin B12 deficiency is characterized metabolically by increased serum and urine methylmalonic acid (MMA). Urinary MMA/creatinine ratio is suggested for screening for metabolic vitamin B12 deficiency in older populations. Results: A UPLC-MS/MS method for the analysis of urinary MMA and creatinine was developed/validated. A good separation of MMA from succinic acid, its structural isomer, was achieved. Intra- and interday accuracy biases and precision coefficients were all ≤6.3% for MMA and creatinine. Urine and serum samples of 34 individuals of the NuAge Biobank were analyzed for technical comparisons showing that urinary MMA/creatinine ratios by UPLC-MS/MS strongly correlated with GC-MS values, and with serum MMA values. Conclusion: The UPLC-MS/MS method developed is rapid/reliable for the analysis of urinary MMA/creatinine ratios.
Assuntos
Ácido Metilmalônico/urina , Deficiência de Vitamina B 12/metabolismo , Deficiência de Vitamina B 12/urina , Idoso , Idoso de 80 Anos ou mais , Cromatografia Líquida de Alta Pressão , Avaliação Pré-Clínica de Medicamentos , Feminino , Cromatografia Gasosa-Espectrometria de Massas , Humanos , Masculino , Espectrometria de Massas em TandemRESUMO
An important aspect to understand about an experimental molecule in drug discovery is its stability in solution. A compound that degrades might be eliciting its apparent effect via a degradation product, so it is important to understand the solution stability profile of a compound early on in the drug discovery process. Improvements and application of a streamlined, higher-throughput method for testing solution stability to support drug discovery are described. Mass spectrometry detection has been incorporated into the screen to allow for the identification of degradation products. The amount of compound needed for the assay has been significantly reduced using 10 mM DMSO solutions instead of solid material. The buffers used in the screen provide the stability-pH profile of compounds with additional variations to assess liabilities under oxidizing and reducing conditions. In this article, we discuss the method development, screen validation, guidelines for result interpretation, and results for a set of marketed drugs to illustrate the application of the screen.
Assuntos
Desenvolvimento de Medicamentos/métodos , Descoberta de Drogas/métodos , Avaliação Pré-Clínica de Medicamentos/métodos , Cromatografia Líquida , Desenvolvimento de Medicamentos/normas , Descoberta de Drogas/normas , Avaliação Pré-Clínica de Medicamentos/normas , Estabilidade de Medicamentos , Ensaios de Triagem em Larga Escala , Humanos , Concentração de Íons de Hidrogênio , Espectrometria de Massas , Oxirredução , Solubilidade , SolventesRESUMO
Consistent with the large-scale use of pesticide seed treatments in U.S. field crop production, there has been an increased use of neonicotinoid-treated corn and soybean seed over the past decade. Neonicotinoids can move downwind to adjacent off-field pollinator habitats in dust from planting and/or move downslope to habitats in surface water. The extent of potential neonicotinoid exposure to pollinators from neonicotinoid movement into these adjacent pollinator habitats is unclear. Pollen and leaf tissue extractions were completed using a quick, easy, cheap, effective, rugged, and safe (QuEChERS) extraction procedure. Samples were subjected to a clean-up step using dispersive solid-phase extraction (dSPE) techniques prior to analysis. The compounds in the extracts were separated on a reversed-phase column with gradient elution and confirmed with tandem mass spectrometry. The extraction method showed acceptable recoveries of analytes ranging from 78.4 to 93.6% and 89.4 to 101% for leaf tissue and pollen, respectively. The method's detection limits ranged from 0.04 to 0.3 ng/g in milkweed leaf tissue and 0.04 to 1.0 ng/g in pollen. The method is currently being employed in ongoing studies surveying pollen from a diversity of forbs and milkweed leaves obtained from habitat patches established within fields with a history of using neonicotinoid-treated seeds.
Assuntos
Monitoramento Ambiental/métodos , Neonicotinoides/análise , Pólen/química , Asclepias/química , Guanidinas , Inseticidas/análise , Nitrocompostos , Oxazinas , Resíduos de Praguicidas/análise , Folhas de Planta/química , Polinização , Sementes/química , Poluentes do Solo/análise , Extração em Fase Sólida/métodos , Espectrometria de Massas em Tandem/métodos , TiazóisRESUMO
Beans provide a rich source of plant-based proteins and carbohydrates. It is well documented in the literature that the raffinose family of oligosaccharides (RFOs: raffinose, stachyose, and verbascose) is linked with flatulence issues. In this study, the soluble sugar content of 23 dry beans was investigated using a newly developed and validated analytical method with high-performance anion-exchange chromatography coupled to an amperometric pulse detection. All seven sugars (galactose, glucose, fructose, sucrose, raffinose, stachyose, and verbascose) showed good linearity (r2 ≥ 0.99) between 0.156 and 20 µg/mL. The limit of detection and quantification were determined as 0.01-0.11 µg/mL and 0.04-0.32 µg/mL, respectively. Significant variations in the profiles and concentrations of individual and total sugars were observed in 23 dry beans. Sucrose and stachyose were the two prominent soluble sugars combinedly representing an average of 86% of the total soluble sugars. Yellow split beans, large lima, and black eyed peas contained higher amounts of total soluble sugars (79.8-83.6 mg/g), whereas lower amounts were observed in speckled butter peas and lentils (53.6-56.6 mg/g). Garbanzo beans contained maximum levels of mono and disaccharides (MD), and yellow split beans showed the highest levels of RFOs. Based on the hierarchical cluster analysis of the total soluble sugars (TS), MD, RFOs, and MD/RFOs ratio, 23 beans can be classified into five groups. The average TS content and the MD/RFOs ratios of the five groups were determined as group 1 (TS = 55.1 mg/g and MD/RFOs = 0.30), group 2 (TS = 77.6 mg/g and MD/RFOs = 0.31), group 3 (TS = 78.3 mg/g and MD/RFOs = 0.51), group 4 (TS = 59.1 mg/g and MD/RFOs = 1.06), and group 5 (TS = 68.5 mg/g and MD/RFOs = 0.62). This information is useful for researchers, food industries, and consumers that are looking for plant-based protein source as an alternative to animal proteins with reduced flatulence problems.
Assuntos
Oligossacarídeos/química , Phaseolus/química , Extratos Vegetais/química , Carboidratos da Dieta/análise , Phaseolus/classificação , Sementes/químicaRESUMO
The paper presents development and validation of a RP-HPLC-PDA method for quantification of 30 phenolic constituents of the blackthorn (Prunus spinosa L.) flower, a traditional European herbal medicine with a unique and complex composition. The target analytes were selected from over 50 active compounds present in the investigated plant material, and their separation was optimized on a C18 Ascentis Express fused-core column (2.7 µm, 150 mm × 4.6 mm), in a step-by-step process, in terms of elution solvents, gradient profile, temperature, and flow rate. The final procedure was carried out with an acetonitrile-tetrahydrofuran gradient at a flow rate of 1.09 mL/min and column temperature of 28°C. Under those conditions, the matrix peaks were satisfactorily separated within 35 min. The validation showed good precision (RSD < 5 %), accuracy (93.5-102.1 %), linearity (r > 0.9998), and sensitivity (LODs 0.51-2.05â¯ng) of the method. The real sample analysis demonstrated its applicability for quantification of the phenolics both in commercial samples of P. spinosa flowers (different manufacturers and years of collection), as well as in the extracts (of different polarity) prepared thereof. Thus, the developed procedure proved to be a useful tool in quality control, and the optimization approach might serve as a practical guideline for LC-method development in complex matrices.