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1.
Ecotoxicol Environ Saf ; 202: 110942, 2020 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-32800224

RESUMO

Spinetoram (XDE-175-J/L), a new spinosyn-based insecticide, is one of the most widely used bio-pesticide worldwide and its registration for direct application on cauliflower to control Plutella xylostella is currently under review in China. In this study, an accredited method for simultaneous determination of spinetoram and its two metabolites in cauliflower was established and validated using QuEChERS (quick, easy, cheap, effective, rugged, and safe) preparation coupled with ultra-liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). The average recoveries using this method were ranged from 74 to 99% with relative standard deviations (RSDs) of 2.4-10.5%. The dissipation kinetics and terminal residues of spinetoram and its two metabolites in cauliflower were studied in Tianjin and Guizhou over two years under open field conditions. The dissipation experiments revealed that spinetoram was swiftly degraded in cauliflower, with the half-lives less than or equal to 4.85 days. The terminal residues of total spinetoram (sum of spinetoram and its two metabolites) detected in cauliflower samples were in the range of 0.009 mg/kg-0.337 mg/kg. Dietary risk assessment study was implemented based on the scientific data of field trials, food consumption and acceptable daily intake (ADI). The estimated long-term dietary risk probability (RQ) of total spinetoram from cauliflower was between 5.79% and 5.91%, indicating that spinetoram was associated with acceptable risk for dietary cauliflower consumption. The results would provide scientific guidance for proper usage of spinetoram in cauliflower field ecosystem.


Assuntos
Brassica/fisiologia , Inseticidas/toxicidade , Macrolídeos/toxicidade , China , Cromatografia Líquida/métodos , Dieta , Ecossistema , Inseticidas/análise , Cinética , Resíduos de Praguicidas/análise , Medição de Risco , Espectrometria de Massas em Tandem/métodos
2.
J Chromatogr A ; 1626: 461324, 2020 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-32797817

RESUMO

Sorption of PFASs onto surfaces of laboratory materials has been frequently reported. Due to the often complex and poorly understood nature of such sorption, workarounds have often included use of whole samples only, accompanied by sample vessel rinsing to desorb active surfaces. The resulting methods tend to require considerable sample preparation times and preclude typical activities such as aliquoting and dilution of water samples prior to extraction. This manuscript reports an approach for PFAS analysis which uses subsampling of water matrices from vessels including centrifuge tubes and autosampler vials, through the optimized use of solvent to reduce PFAS retention on subsampling vessels. Online solid phase extraction (SPE) using a weak anion exchange resin is then used to concentrate sample aliquots to improve sensitivity and allow for removal of matrix interferences. With the technique of ultra performance liquid chromatography (UPLC) coupled to isotope dilution tandem mass spectrometry, statistically based quantitation limits ranged from sub ng/L to single digit ng/L for carboxylate, sulfonate, and sulfonamide PFASs analytes from C4 to C12. Linear calibration ranges were from 0.25 to 4000 ng/L. Matrix effects relevant for drinking water treatment studies, such as cations, organic carbon, and competing PFAS compounds, were evaluated and found to not impact method performance within QC criteria consistent with study data quality objectives.


Assuntos
Fluorcarbonetos/análise , Indicadores e Reagentes/análise , Espectrometria de Massas em Tandem/métodos , Cromatografia Líquida de Alta Pressão , Fluorcarbonetos/isolamento & purificação , Água Doce/análise , Indicadores e Reagentes/isolamento & purificação , Marcação por Isótopo , Sais/química , Extração em Fase Sólida , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/isolamento & purificação
3.
J Chromatogr A ; 1627: 461399, 2020 Sep 13.
Artigo em Inglês | MEDLINE | ID: mdl-32823104

RESUMO

Citrinin is a toxic small organic molecule produced as a secondary metabolite by fungi types Penicillium, Monascus and Aspergillus and is known to contaminate various food commodities during postharvest stages of food production. During the last 10 years, most reported methods for citrinin analysis employed enzyme-linked immunosorbent assays or high-performance liquid chromatography. Over this same time period, liquid extraction, solid-phase extraction, dispersive liquid-liquid microextraction and QuEChERS were the most cited sample preparation and clean-up methods. In this review the advantages and disadvantages of the various sample preparation, separation and detection methods for citrinin analysis over the last decade are evaluated. Furthermore, current trends, emerging technologies and the future prospects of these methods are discussed.


Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Citrinina/análise , Espectrometria de Massas em Tandem/métodos , Aspergillus/metabolismo , Citrinina/isolamento & purificação , Citrinina/urina , Ensaio de Imunoadsorção Enzimática , Contaminação de Alimentos/análise , Humanos , Microextração em Fase Líquida , Monascus/metabolismo , Extração em Fase Sólida
4.
J Chromatogr A ; 1627: 461403, 2020 Sep 13.
Artigo em Inglês | MEDLINE | ID: mdl-32823108

RESUMO

Dopamine is a catecholamine neurotransmitter that degrades rapidly in aqueous solutions; hence, its analysis following brain microdialysis is challenging. The aim of the current study was to develop and validate a new microdialysis coupled LC-MS/MS system with improved accuracy, precision, simplicity and turnaround time for dopamine, serotonin, methamphetamine, amphetamine, 4-hydroxymethamphetamine and 4-hydroxyamphetamine analysis in the brain. Dopamine degradation was studied with different stabilizing agents under different storage conditions. The modified microdialysis system was tested in vitro, and was optimized for best probe recovery, assessed by %gain. LC-MS/MS assay was developed and validated for the targeted compounds. Stabilizing agents (ascorbic acid, EDTA and acetic acid) as well as internal and cold standards were added on-line to the dialysate flow. Assay linearity range was 0.01-100 ng/mL, precision and accuracy passed criteria, and LOQ and LLOQ were 0.2 and 1.0 pg, respectively. The new microdialysis coupled LC-MS/MS system was used in Wistar rats striatum after 4 mg/kg subcutaneous methamphetamine. Methamphetamine rapidly distributed to rat striatum reaching an average ~200 ng/mL maximum, ~82.5 min post-dose. Amphetamine, followed by 4-hydroxymethamphetamine, was the most abundant metabolite. Dopamine was released following methamphetamine injection, while serotonin was not altered. In conclusion, we proposed and tested an innovative and simplified solution to improve stability, accuracy and turnover time to monitor unstable molecules, such as dopamine, by microdialysis.


Assuntos
Encéfalo/metabolismo , Dopamina/análise , Metanfetamina/análise , Serotonina/análise , Espectrometria de Massas em Tandem/métodos , Animais , Cromatografia Líquida de Alta Pressão , Dopamina/isolamento & purificação , Dopamina/metabolismo , Meia-Vida , Masculino , Metanfetamina/isolamento & purificação , Metanfetamina/metabolismo , Microdiálise , Ratos , Ratos Wistar , Serotonina/isolamento & purificação , Serotonina/metabolismo
5.
J Anal Toxicol ; 44(7): 708-717, 2020 Oct 12.
Artigo em Inglês | MEDLINE | ID: mdl-32808043

RESUMO

An analytical method for the detection of 40 benzodiazepines, (±)-zopiclone, zaleplon and zolpidem in blood and urine by solid-phase extraction liquid chromatography-tandem mass spectrometry was developed and validated. Twenty-nine of 43 analytes were quantified in 0.5 mL whole blood for investigating postmortem, drug-facilitated sexual assault (DFSA) and driving under the influence of drugs cases (DUID). The four different dynamic ranges of the seven-point, linear, 1/x weighted calibration curves with lower limits of quantification of 2, 5, 10 and 20 µg/L across the analytes encompassed the majority of our casework encountered in postmortem, DFSA and DUID samples. Reference materials were available for all analytes except α-hydroxyflualprazolam, a hydroxylated metabolite of flualprazolam. The fragmentation of α-hydroxyflualprazolam was predicted from the fragmentation pattern of α-hydroxyalprazolam, and the appropriate transitions were added to the method to enable monitoring for this analyte. Urine samples were hydrolyzed at 55°C for 30 min with a genetically modified ß-glucuronidase enzyme, which resulted in >95% efficiency measured by oxazepam glucuronide. Extensive sample preparation included combining osmotic lysing and protein precipitation with methanol/acetonitrile mixture followed by freezing and centrifugation resulted in exceptionally high signal-to-noise ratios. Bias and between-and within-day imprecision for quality controls (QCs) were all within ±15%, except for clonazolam and etizolam that were within ±20%. All 29 of the 43 analytes tested for QC performance met quantitative reporting criteria within the dynamic ranges of the calibration curves, and 14 analytes, present only in the calibrator solution, were qualitatively reported. Twenty-five analytes met all quantitative reporting criteria including dilution integrity. The ability to analyze quantitative blood and qualitative urine samples in the same batch is one of the most useful elements of this procedure. This sensitive, specific and robust analytical method was routinely employed in the analysis of >300 samples in our laboratory over the last 6 months.


Assuntos
Benzodiazepinas/metabolismo , Hipnóticos e Sedativos/metabolismo , Detecção do Abuso de Substâncias/métodos , Alprazolam/análogos & derivados , Compostos Azabicíclicos/sangue , Compostos Azabicíclicos/metabolismo , Compostos Azabicíclicos/urina , Benzodiazepinas/sangue , Benzodiazepinas/urina , Cromatografia Líquida/métodos , Diazepam/análogos & derivados , Toxicologia Forense , Humanos , Hipnóticos e Sedativos/análise , Hipnóticos e Sedativos/sangue , Hipnóticos e Sedativos/urina , Limite de Detecção , Piperazinas/sangue , Piperazinas/metabolismo , Piperazinas/urina , Medicamentos Indutores do Sono/sangue , Medicamentos Indutores do Sono/metabolismo , Medicamentos Indutores do Sono/urina , Extração em Fase Sólida/métodos , Espectrometria de Massas em Tandem/métodos , Zolpidem/sangue , Zolpidem/metabolismo , Zolpidem/urina
6.
PLoS One ; 15(8): e0236297, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32780750

RESUMO

Naproxen is a widely used non-steroidal anti-inflammatory drug for the control of postoperative inflammatory signs and symptoms in dentistry. Its association with esomeprazole has been widely studied and has yielded good results for the control of acute pain, even with the delayed absorption of naproxen owing to the presence of esomeprazole. To further understand the absorption, distribution, and metabolism of this drug alone and in combination with esomeprazole, we will analyze the pharmacokinetic parameters of naproxen and its major metabolite, 6-O-desmethylnaproxen, in saliva samples. A rapid, sensitive, and selective liquid chromatography-tandem mass spectrometric method for the simultaneous determination of naproxen and 6-O-desmethylnaproxen in saliva will be developed and validated. Sequential saliva samples from six patients will be analyzed before and 0.25, 0.5, 0.75, 1, 1.5, 2, 3, 4, 5, 6 8, 11, 24, 48, 72, and 96 h after the ingestion of one naproxen tablet (500 mg) and esomeprazole-associated naproxen tablets (500 + 20 mg), at two different times. After liquid-liquid extraction with ethyl acetate and HCl, the samples will be analyzed using an 8040 Triple Quadrupole Mass Spectrometer (Shimadzu, Kyoto, Japan). Separation of naproxen and its major metabolic products will be performed using a Shim-Pack XR-ODS 75Lx2.0 column and C18 pre-column (Shimadzu, Kyoto, Japan) at 40°C using a mixture of methanol and 10 mM ammonium acetate (70:30, v/v) with an injection flow of 0.3 mL/min. The total analytical run time will be 5 min. The detection and quantification of naproxen and its metabolite will be validated, which elucidate the pharmacokinetics of this drug, thereby contributing to its proper prescription for the medical and dental interventions that cause acute pain.


Assuntos
Anti-Inflamatórios não Esteroides/farmacocinética , Monitoramento de Medicamentos/métodos , Esomeprazol/farmacocinética , Naproxeno/análogos & derivados , Saliva/química , Administração Oral , Adolescente , Adulto , Anti-Inflamatórios não Esteroides/isolamento & purificação , Cromatografia Líquida de Alta Pressão/métodos , Relação Dose-Resposta a Droga , Combinação de Medicamentos , Esomeprazol/administração & dosagem , Esomeprazol/isolamento & purificação , Feminino , Absorção Gastrointestinal , Humanos , Masculino , Metanol/química , Pessoa de Meia-Idade , Naproxeno/administração & dosagem , Naproxeno/isolamento & purificação , Naproxeno/farmacocinética , Dor Processual/tratamento farmacológico , Reprodutibilidade dos Testes , Comprimidos , Espectrometria de Massas em Tandem/métodos , Adulto Jovem
7.
J Chromatogr A ; 1626: 461353, 2020 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-32797833

RESUMO

This paper reports the development of an LC-ESI-MS2 method for the sensitive determination of hydroxylated polychlorinated biphenyls (OH-PCBs) in human serum samples. Congener-specific separation was achieved by using a polar-embedded stationary phase, previously optimized for the working group, which provided better separation of isobaric compounds than the common octadecylsilane phases. MS fragmentation patterns and energies showed differences among OH-PCB congeners, mainly depending on the position of OH-group and the number of chlorine atoms in the molecule, although the most intense transitions were always those corresponding to the neutral loss of an HCl group from the quasi-molecular ion cluster. The method allowed the determination of OH-PCBs with good linearity (dynamic linear range of four orders of magnitude with R2 higher than 0.995) and precision (relative standard deviations of absolute areas lower than 10%), and with better sensitivity than other similar methods previously described in the literature. Matrix effect has been evaluated and reduced to less than 10% by the addition of isotopically labeled standards and a 10-fold dilution of the final sample extract. The low iLODs provided by the developed method (from 1.2 to 5.4 fg µL-1 for all the OH-PCBs studied, except 4'-OHCB108, whose iLOD was 61 fg µL-1) allows dilution without losses of detected peaks. Finally, the applicability of the method has been demonstrated by analyzing human serum samples belonging to an interlaboratory exercise.


Assuntos
Cromatografia Líquida/métodos , Cromatografia de Fase Reversa/métodos , Bifenilos Policlorados/análise , Espectrometria de Massas em Tandem/métodos , Humanos , Hidroxilação , Bifenilos Policlorados/sangue , Bifenilos Policlorados/química , Espectrometria de Massas por Ionização por Electrospray
8.
J Chromatogr A ; 1626: 461356, 2020 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-32797836

RESUMO

The presence of organophosphate esters (OPEs) in everyday commodities such as furniture, household appliances and baby toys have rendered these contaminants ubiquitous in environmental fates such as air, water, soils and biota. Their presence in food-related species suggests that an additional route of exposure to these esters for the general population is fish intake through diet. Their incipient toxicity and carcinogenetic behaviour make it essential to develop methods for determining OPEs in fish samples. In this paper we have developed a new method for determining 9 OPEs based on the QuEChERS extraction method followed by a simple clean-up using a novel device for selective lipid removal (LipiFiltr) and GC-MS/MS to extract these compounds from fish samples regardless of lipid content. QuEChERS salt packet optimisation and clean-up strategies such as liquid-liquid extraction, dispersive-solid phase extraction and LipiFiltr were tested. Our results showed that EN 15662 method salts and Lipifiltr were the best combination to produce efficient analyte apparent recovery (67-116%) and negligible matrix effects (<10%). Limits of detection ranged from 0.05 ng g-1 (dry weight) for TiBP and TBP to 2.00 ng g-1 (dry weight) for TCEP. Fish samples from four fish species were determined with a median concentration of ΣOPEs 5.31 ng g-1 on a wet weight basis, with TBP, TiBP and TCPP as the main contenders. Estimates of exposure and risk associated with consuming these compounds via dietary intake showed low levels of concern for the population of Tarragona.


Assuntos
Ésteres/análise , Peixes/metabolismo , Retardadores de Chama/análise , Cromatografia Gasosa-Espectrometria de Massas/métodos , Organofosfatos/análise , Plastificantes/análise , Medição de Risco , Espectrometria de Massas em Tandem , Adolescente , Adulto , Idoso , Animais , Criança , Dieta , Monitoramento Ambiental , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Espectrometria de Massas em Tandem/métodos , Adulto Jovem
9.
J Chromatogr A ; 1627: 461413, 2020 Sep 13.
Artigo em Inglês | MEDLINE | ID: mdl-32823111

RESUMO

Innovations in extraction phases, extraction modes and hyphenated instrument configurations, are the most important issues to address for progress in the solid phase microextraction (SPME) methodology. In this regard, we have embarked on the development of a novel biocompatible 96-monolithic inorganic hollow fiber (96-MIHF) array as a new configuration for high-throughput SPME on a 96-well plate system. An arrangement of highly ordered 96 titania/Hydroxyapatite (TiO2/HAP) nanocomposite hollow fibers and corresponding stainless-steel needles on a Teflon plate holder were used as the extraction module. The inorganic hollow fibers were prepared via a rapid and reproducible template approach (Polypropylene hollow fiber) in combination with a sol-gel method in the presence of polyvinyl alcohol (PVA), as a network maker. The hollow fiber-shape sorbents were obtained with excellent precision by weight (RSD% = 4.98, n = 10) and length (RSD% = 1.08, n = 10) criteria. The proposed design can overcome a number of geometrically dependent drawbacks of conventional high-throughput SPME methods, mainly the ones related to sorbent amount and surface area due to possessing inner/outer surfaces without additional internal supports. The SPME platform, for the first time, was successfully applied for the extraction and preconcentration of doxorubicin from urine and water media without requiring sample preparation and free from significant matrix effect. The extracted analyte was analyzed by liquid chromatography-ion trap tandem mass spectrometry (LC-MS/MS). Highly satisfactory analytical figures of merit were obtained under optimized conditions. The limit of detection (LOD), limit of quantification (LOQ) and linearity of determination were 0.1 ng mL-1, 0.25 ng mL-1 and 0.25 to 4000 ng mL-1, respectively. The interday, intraday and inter sorbent precisions for three concentration levels ranged from 2.01 to 8.09 % (n = 3), 1.02 to 8.65 % (n = 5) and 0.99 to 1.02% (n = 15), respectively. The mean intra-well RSD value for 96 individual wells in 96-MIHF-SPME-LC-MS/MS (n = 3) at the medium concentration level was 7.81%.


Assuntos
Cromatografia Líquida/métodos , Doxorrubicina/urina , Microextração em Fase Sólida/métodos , Espectrometria de Massas em Tandem/métodos , Água/química , Adolescente , Adulto , Daunorrubicina/urina , Feminino , Humanos , Concentração de Íons de Hidrogênio , Limite de Detecção , Masculino , Pessoa de Meia-Idade , Concentração Osmolar , Polipropilenos/química , Porosidade , Reprodutibilidade dos Testes , Fatores de Tempo , Adulto Jovem
10.
J Chromatogr A ; 1627: 461416, 2020 Sep 13.
Artigo em Inglês | MEDLINE | ID: mdl-32823114

RESUMO

Animal feeds are often reported to be contaminated with chemical residues, and when present above the maximum legal limit, these compounds can cause harmful effects to consumers of animal produce. Thus, animal feed safety is an important regulatory concern. The aim of this study was to optimise a multiresidue method for the simultaneous analysis of multi-class pesticides and a number of frequently used veterinary drugs using LC-MS/MS and GC-MS/MS. The method was validated in a range of feed matrices, including maize feed, poultry feed and mixed feed concentrate. The optimised sample preparation workflow involved extraction of feeds (5 g) with ethyl acetate (10 mL), followed by a freezing step (at -20°C) used for eliminating the matrix co-extractives. The extract was further cleaned by dispersive solid phase extraction with a combination of primary secondary amine, C18 and florisil sorbents. From the cleaned-extract, an aliquot was analysed by GC-MS/MS, while another portion of it was solvent-exchanged to acetonitrile:water (50:50) and then analysed by LC-MS/MS. This method effectively minimised the matrix interferences. A total of 192 pesticides was analysed by GC-MS/MS within a runtime of 22 min. The LC-MS/MS method was validated for 187 compounds including 17 veterinary drugs. For most of the compounds, the limit of quantification (LOQ) was 0.01 mg/kg. The recoveries at LOQ and higher levels ranged between 70% and 120%, with precision-RSDs of < 20%. The method provided a precise analysis in a wide range of market-feed samples. As shown, the method is suitable for regulatory and commercial testing purposes.


Assuntos
Ração Animal/análise , Cromatografia Líquida/métodos , Praguicidas/análise , Espectrometria de Massas em Tandem/métodos , Drogas Veterinárias/análise , Animais , Congelamento , Cromatografia Gasosa-Espectrometria de Massas , Limite de Detecção , Resíduos de Praguicidas/análise , Reprodutibilidade dos Testes , Solventes/química , Água/química
11.
J Chromatogr A ; 1627: 461421, 2020 Sep 13.
Artigo em Inglês | MEDLINE | ID: mdl-32823116

RESUMO

Herein we present an efficient, column-switching method that relies on a custom-made T-union passive diffusion micromixer to assist water dilution and promote trap solute focusing of a high sample volume dissolved in pure organic solvent using a 0.075 mm i.d. nano-LC column. This method allows injecting 20 µL (or higher) of sample volume, speeding up the analysis time, with a 400-fold increase of the limits of quantitation for selected compounds. Five pesticides in different media were used as model compounds, and the analyses were carried out with a triple quadrupole mass spectrometer equipped with a Liquid Electron Ionization (LEI) LC-MS interface working in multiple reaction monitoring (MRM) mode. The system microfluidics were investigated using COMSOL modeling software. Robustness of the entire system was evaluated using a post-extraction addition soil extracts with limits of detection values spanning from 0.10 to 0.45 µg/L. Reproducible results in terms of peak area, peak shape, and retention times were achieved in soil matrix. Repeatability test on peak area variations were lower than 10%.


Assuntos
Cromatografia de Fase Reversa/métodos , Elétrons , Microfluídica/métodos , Nanopartículas/química , Espectrometria de Massas em Tandem/métodos , Água/química , Acetonitrilos/química , Difusão , Limite de Detecção , Praguicidas/análise , Reprodutibilidade dos Testes , Solventes/química
12.
Chemosphere ; 255: 127034, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32679634

RESUMO

Due to the increasing presence of plastic and plastic associated contaminants in the aquatic environments, the monitoring of this contamination in fish products and the understanding of possible human health implications is considered urgent. However, data are still relatively scarce, mostly due to the methodological challenges in the chemical analysis: these contaminants are ubiquitous and procedural contamination from the laboratory is frequent. In this work, we compared solid-phase microextraction (SPME) to ultrasonic assisted solvent extraction (UASE) as sample preparation methods for the liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) determination of phthalates in fish fillets. UASE was carried out with an acetone-hexane (1:1) solution and according to a reference procedure aimed to obtain the exhaustive extraction of the target analytes. SPME was carried out by applying C18 fibers in direct immersion mode and by using water/methanol 20:80 mixture to desorb the aliquot required for the analysis. Overall, SPME displayed an improved control of the background contamination and enabled lower LOQs. Precision, calculated as relative standard deviation (RSD) on replicates of a reference sample, was below 24% for both the method. Analysis of real samples purchased from Italian supermarkets showed that SPME might be an efficient tool for estimating the risk associated with fish consumption.


Assuntos
Peixes/metabolismo , Ácidos Ftálicos/metabolismo , Poluentes Químicos da Água/metabolismo , Animais , Cromatografia Líquida/métodos , Microextração em Fase Sólida/métodos , Solventes/química , Espectrometria de Massas em Tandem/métodos , Ultrassom
13.
J Chromatogr A ; 1625: 461343, 2020 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-32709308

RESUMO

A simple magnetic dispersive solid-phase extraction (MDSPE) methodology based on mesoporous Fe3O4@ succinic acid nanospheres and high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) has been developed to determine kanamycin (KNM) and neomycin (NEO) contents in Measles, Mumps, and Rubella (MMR) vaccine products. The monodispersed mesoporous Fe3O4 nanospheres with self-assembled carboxyl terminated shell have been prepared via a simple solvothermal method. These as-synthesized mesoporous Fe3O4 nanospheres showed a high magnetic saturation value (Ms = 46 emu g-1) and large specific surface area (111.12 m2 g-1) which made them potential candidates as sorbents in magnetic solid-phase extraction. The adsorption experimental data fitted well with the Freundlich-Langmuir isotherm and followed a pseudo-second-order kinetic model. Moreover influential parameters on extraction efficiency were investigated and optimized. Under optimal conditions, the limits of detection for KNM and NEO were 1.0 and 0.1 ng mL-1, respectively. Recovery assessments using real samples exhibited recoveries in the range of 96.0 ± 4.3 to 101.5 ± 7.1 %, with relative standard deviations of <10.7% (for intra- day) and <14.6% (for inter- day). The proposed method was successfully applied for different spiked and un-spiked MMR vaccine samples. The presented extraction method provides a fast, selective, robust and practical platform for the detection of KNM and NEO in MMR vaccine samples.


Assuntos
Dextranos/química , Canamicina/análise , Nanopartículas de Magnetita/química , Vacina contra Sarampo/análise , Caxumba/imunologia , Nanosferas/química , Neomicina/análise , Vacina contra Rubéola/análise , Espectrometria de Massas em Tandem/métodos , Adsorção , Cromatografia Líquida de Alta Pressão , Concentração de Íons de Hidrogênio , Cinética , Limite de Detecção , Magnetismo , Nanosferas/ultraestrutura , Reprodutibilidade dos Testes , Extração em Fase Sólida , Solventes/química , Espectroscopia de Infravermelho com Transformada de Fourier , Ácido Succínico/química , Fatores de Tempo , Água/química
14.
J Chromatogr A ; 1625: 461306, 2020 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-32709349

RESUMO

A pentafluorobenzoylation (PFBz)-liquid chromatography-tandem mass spectrometry method was developed for qualitative and quantitative analysis of ethanolamines (EAs, nitrogen mustard degradation products). With this method, highly hydrophilic EAs can be sufficiently analyzed with a commonly used reversed phase column (retention times: (PFBz)2-methyl diethanolamine, 9.1 min; (PFBz)2-ethyl diethanolamine, 9.8 min; and (PFBz)3-triethanolamine, 17.6 min). The applicability of the method for real samples was investigated via recovery tests. Methyl diethanolamine and ethyl diethanolamine were detected at concentrations as low as 1 ng/mL in serum and 10 ng/mL in urine, and quantified within the range of 1-1000 ng/mL and 10-1000 ng/mL, respectively.


Assuntos
Cromatografia Líquida/métodos , Fluorbenzenos/química , Mecloretamina/análise , Espectrometria de Massas em Tandem/métodos , Etanolamina/sangue , Humanos , Hidrólise , Interações Hidrofóbicas e Hidrofílicas , Limite de Detecção
15.
J Chromatogr A ; 1625: 461226, 2020 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-32709310

RESUMO

In this work, an easy and fast procedure for the selective multiresidue determination of 14 highly polar pesticides (including glyphosate, glufosinate, ethephon and fosetyl) and metabolites in beverages is presented. After an initial sample dilution (1:1, v/v), the extract is shaken and centrifuged, further diluted and then injected directly into the LC-MS/MS system, using hydrophilic interaction liquid chromatography (HILIC) and tandem mass spectrometry. No clean-up procedure was needed. The method was validated according to the current European guidelines for pesticide residue analysis in food and feed and linearity, limits of detection and quantification, matrix effects, trueness and precision were assessed. For plant-based milk, wine and beer samples, 10, 11 and 12 analytes, respectively, out of 14 were fully validated at 10 µg kg-1, the lowest spike level tested. The matrix effect was negative in most of the cases, showing for some compounds, such as HEPA, up to 80% suppression when compared to the response from standards in solvent. The use of isotopically labelled internal standards is required for the optimal quantification, as it compensates for high and varying matrix effects and also for recovery losses during extraction.


Assuntos
Cerveja/análise , Cromatografia Líquida de Alta Pressão/métodos , Substitutos do Leite/química , Resíduos de Praguicidas/análise , Espectrometria de Massas em Tandem/métodos , Vinho/análise , Animais , Ânions/química , Interações Hidrofóbicas e Hidrofílicas , Leite de Soja/química
16.
J Chromatogr A ; 1625: 461233, 2020 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-32709312

RESUMO

Untargeted metabolomics can be a great tool for exploring new scientific areas; however, wrong metabolite annotation questions the credibility and puts the success of the entire research at risk. Therefore, an effort should be made to improve the quality and robustness of the annotation despite of the challenges, especially when final identification with standards is not possible. Through non-targeted analysis of human plasma samples, from a large cancer cohort study using RP-LC-ESI-QTOF-MS/MS, we have resolved MS/MS annotation through spectral matching, directed to hydroxyeicosatetraenoic acids (HETEs) and, MS/MS structural elucidation for newly annotated oxidized lyso-phosphatidylcholines (oxLPCs). The annotation of unknowns is supported with structural information from fragmentation spectra as well as the fragmentation mechanisms involved, necessarily including data from both polarity modes and different collision energies. In this work, we present evidences that various oxidation products show significant differences between cancer patients and control individuals and we establish a workflow to help identify such modifications. We report here the upregulation of HETEs and oxLPCs in patients with neuroendocrine tumors (NETs). To our knowledge, this is the first attempt to determine HETEs in NETs and one of very few studies where oxLPCs are annotated. The obtained results provide an important insight regarding lipid oxidation in NETs, although their physiological functions still have to be established and require further research.


Assuntos
Lipídeos/sangue , Metaboloma , Adulto , Idoso , Idoso de 80 Anos ou mais , Axitinibe/uso terapêutico , Cromatografia Líquida de Alta Pressão , Cromatografia de Fase Reversa , Feminino , Humanos , Peroxidação de Lipídeos , Lipídeos/química , Lipídeos/isolamento & purificação , Lisofosfatidilcolinas/sangue , Lisofosfatidilcolinas/química , Lisofosfatidilcolinas/isolamento & purificação , Masculino , Pessoa de Meia-Idade , Tumores Neuroendócrinos/tratamento farmacológico , Tumores Neuroendócrinos/metabolismo , Tumores Neuroendócrinos/patologia , Análise de Componente Principal , Espectrometria de Massas em Tandem/métodos
17.
J Chromatogr A ; 1625: 461243, 2020 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-32709315

RESUMO

The long identified toxic gas, hydrogen sulfide (H2S), which has also been confirmed as the third gaseous signaling molecule following NO and CO, plays important roles in various physiological and pathological process. The current most established quantification method for H2S is HPLC method coupled with fluorescence detection after derivatization with a costly fluorescent reagent, Monobromobimane (MBB). However, The MBB method is characterized by strict reaction condition, long reaction time, tedious operation, and inconsistent reported results. In this study, based on the thiolysis reaction of 7-nitro-2, 1, 3-benzoxadiazole (NBD) ether, the commonly used chromatographic modifier 4-chloro-7-nitro-2,1,3- benzoxadiazole (NBDCl) and four probes (NBDOMe, NBDOEt, NBDOTFE and NBDOCMR) synthesized from NBDCl were tested as alternatives for fast quantification of H2S by LC-MS/MS. The reaction product between NBD ethers/NBDCl and H2S showed special pink color visible to the naked eye and was easy to synthesize and separate in lab; it also showed good retention on common chromatographic columns and high instrument response; therefore it is a good determinand. After establishment of LC-MS/MS methods for all the related compounds, the reaction conditions were optimized for all the probes with H2S. Then the stability, selectivity, reaction rate, sensitivity and quantitative linear relationship between the reaction product and H2S concentration were studied for each probe. Finally, NBDOEt was selected for LC-MS/MS detection of H2S. In comparision with the MBB method, the established NBDOEt method showed matched sensitivity and linearity, better selectivity, and higher repeatability; and had the advantages of easy operation, simple reaction condition, and cheap raw materials. The method was successfully validated and applied to determination of Na2S content in Na2S∙9H2O bulk drug and injection. In conclusion, NBDOEt is a promising option for quantification of H2S in abiotic matrix.


Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Éter/química , Sulfeto de Hidrogênio/análise , Espectrometria de Massas em Tandem/métodos , Compostos Bicíclicos com Pontes/química , Sulfeto de Hidrogênio/química , Concentração de Íons de Hidrogênio , Oxidiazóis/química , Reprodutibilidade dos Testes
18.
J Chromatogr A ; 1625: 461275, 2020 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-32709327

RESUMO

Efficient extraction of polar sulfonamides antibiotics from aqueous samples and food is very challenging, because they are hydrophilic, their concentration is very low, and the matrix is complex. Covalent organic frameworks (COFs), a novel porous organic material, have attracted great attention. In this work, the spherical triphenylbenzene-dimethoxyterephthaldehyde-COFs (TPB-DMTP-COFs) were synthesized by a simple room temperature method, and due to their attractive properties, such as high outstanding acid-base stability, large specific surface area, low skeletal density, inherent porosity and high crystallinity, so TPB-DMTP-COFs as ideal solid phase extraction adsorbents showed excellent adsorption performance for trace polar sulfonamides in food and water. TPB-DMTP-COFs were characterized by scanning electron microscopy, Fourier-transform infrared spectroscopy, powder X-ray diffraction, and so on. The important parameters were optimized to improve the extraction efficiency of TPB-DMTP-COFs toward sulfonamides. Analysis of sulfonamides was performed by liquid chromatography-tandem mass spectrometry. The developed method based on TPB-DMTP-COFs material achieved low limits of detection (0.5-1.0 ng L-1), wide linearity (5-1000 ng L-1), and good repeatability (2.5%-8.7%). The possible extraction mechanism was also discussed. Finally, the method was successfully applied to the enrichment and detection of sulfonamides in environmental water samples and food samples. The present study indicated that TPB-DMTP-COFs had splendid prospects in highly sensitive analysis of other pollutants in complex matrix.


Assuntos
Análise de Alimentos , Estruturas Metalorgânicas/química , Extração em Fase Sólida/métodos , Sulfonamidas/análise , Espectrometria de Massas em Tandem/métodos , Poluentes Químicos da Água/análise , Adsorção , Animais , Cromatografia Líquida , Contaminação de Alimentos/análise , Leite/química , Carne de Porco/análise , Porosidade , Sulfonamidas/química , Água/química
19.
Food Chem ; 332: 127394, 2020 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-32610259

RESUMO

In this study, we present the preparation of a new reverse-phase/phenylboronic-acid (RP/PBA)-type mixed-mode magnetic solid-phase extraction (MSPE) adsorbent for use in the cleanup of amatoxin- and phallotoxin-containing samples intended for ultrahigh-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) analysis. Further, the RP/PBA magnetic microspheres have phenyl and phenylboronic acid groups on their surfaces that selectively adsorb amatoxins and phallotoxins through hydrophobic, π-π, and boronate affinity, significantly reducing matrix effects in UPLC-MS/MS analysis. After systematic optimization, all the standard calibration curves expressed satisfactory linearity (r > 0.9930), limits of detection (0.3 µg/kg), and recovery (97.6%-114.2%). Compared with other reported methods, this method also has the advantages of simple, fast, and efficient operation using relatively small amounts of the MSPE adsorbent. Furthermore, the method was successfully applied in a poisoning incident caused by Lepiota brunneoincarnata Chodat & C. Martín ingestion.


Assuntos
Amanitinas/análise , Ácidos Borônicos/química , Cromatografia Líquida de Alta Pressão/métodos , Cromatografia de Fase Reversa/métodos , Imãs/química , Espectrometria de Massas em Tandem/métodos , Adsorção , Amanitinas/isolamento & purificação , Limite de Detecção , Microesferas , Extração em Fase Sólida
20.
Nat Commun ; 11(1): 3284, 2020 06 29.
Artigo em Inglês | MEDLINE | ID: mdl-32601292

RESUMO

The inner nuclear membrane (INM) selectively accumulates proteins that are essential for nuclear functions; however, overaccumulation of INM proteins results in a range of rare genetic disorders. So far, little is known about how defective, mislocalized, or abnormally accumulated membrane proteins are actively removed from the INM, especially in plants and animals. Here, via analysis of a proximity-labeling proteomic profile of INM-associated proteins in Arabidopsis, we identify critical components for an INM protein degradation pathway. We show that this pathway relies on the CDC48 complex for INM protein extraction and 26S proteasome for subsequent protein degradation. Moreover, we show that CDC48 at the INM may be regulated by a subgroup of PUX proteins, which determine the substrate specificity or affect the ATPase activity of CDC48. These PUX proteins specifically associate with the nucleoskeleton underneath the INM and physically interact with CDC48 proteins to negatively regulate INM protein degradation in plants.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Proteínas de Membrana/metabolismo , Membrana Nuclear/metabolismo , Proteoma/metabolismo , Proteômica/métodos , Arabidopsis/genética , Proteínas de Arabidopsis/genética , Proteínas de Transporte/genética , Proteínas de Transporte/metabolismo , Proteínas de Membrana/genética , Proteínas Associadas aos Microtúbulos/genética , Proteínas Associadas aos Microtúbulos/metabolismo , Membrana Nuclear/genética , Proteínas Nucleares/genética , Proteínas Nucleares/metabolismo , Plantas Geneticamente Modificadas , Complexo de Endopeptidases do Proteassoma/metabolismo , Ligação Proteica , Proteólise , Proteoma/genética , Coloração e Rotulagem/métodos , Espectrometria de Massas em Tandem/métodos , Proteína com Valosina/genética , Proteína com Valosina/metabolismo
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