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1.
Se Pu ; 37(8): 815-823, 2019 Aug 08.
Artigo em Chinês | MEDLINE | ID: mdl-31642251

RESUMO

Phthalates (PAEs) are a class of endocrine-disrupting chemicals. In recent years, the harmful effects of PAEs on human health, in particular their toxicity toward the reproductive system and development, have received significant attention because of their increasing production and usage. PAEs are ubiquitous in the environment and food products, resulting in unavoidable and long-term exposure in humans. Therefore, exposure and risk assessments of PAEs in humans are necessary. Screening and quantification of phthalate metabolites in urine is an important method for evaluating PAEs exposure, and establishing accurate analytical methods for this purpose has become a high priority. Phthalate monoesters and secondary metabolites are the most commonly targeted biomarkers of exposure to short-and long-chain PAEs, respectively. The combination of off-line or on-line solid phase extraction (SPE) with high performance liquid chromatography-tandem mass spectrometry has become the preferred method for the determination of phthalate metabolites. This paper reviews the analytical methods available for the detection of urinary phthalate metabolites and discusses the advantages, limitations, and challenges presented by each method in practical applications.


Assuntos
Biomarcadores/urina , Ácidos Ftálicos/urina , Exposição Ambiental , Humanos , Extração em Fase Sólida , Espectrometria de Massas em Tandem
2.
Se Pu ; 37(10): 1048-1052, 2019 Oct 08.
Artigo em Chinês | MEDLINE | ID: mdl-31642282

RESUMO

A method for the rapid screening of 1,3-dichloro-2-propanol, 2,3-dichloro-1-propanol,3-monochloropropane-1,2-diol, and 2-monochloropropane-1,3-diol in soy sauce was developed based on dispersive solid phase extraction-gas chromatography-high resolution mass spectrometry (GC-HRMS). The samples were extracted by ethyl acetate, cleaned up using N-propylethylenediamine and detected by GC-HRMS. The chloropropanols were quantified by the internal standard method. The results demonstrated that the limits of quantitation of the four chloropropanols were in the range of 0.5-10 µg/kg. The recoveries of the four chloropropanols in soy sauce spiked with three levels varied from 78% to 103%, and the relative standard deviations were no more than 8.8%. The proposed method is simple, accurate, sensitive and suitable for the rapid screening of the four chloropropanols in soy sauce.


Assuntos
Propanóis/análise , Alimentos de Soja/análise , Cromatografia Gasosa-Espectrometria de Massas , Extração em Fase Sólida
3.
Se Pu ; 37(10): 1098-1104, 2019 Oct 08.
Artigo em Chinês | MEDLINE | ID: mdl-31642289

RESUMO

A method based on two-step liquid-liquid extraction-solid phase extraction purification coupled with high performance liquid chromatography-tandem mass spectrometry (LC-MS/MS) was developed for the determination of 11 common sulfonamides in pork. The samples were extracted first with ethyl acetate containing 2%(v/v) formic acid and then with acetone for the second step. The supernatant was degreased with n-hexane and cleaned using an Oasis MCX SPE column. Finally, nitrogen was blown over the obtained mixture, and the mixture was filtered for conducting HPLC-MS/MS analysis. The sulfonamides were detected in the multiple reaction monitoring positive ion mode, and quantification was performed by employing the external standard method with matrix calibration curves. All the 11 sulfonamides demonstrated good linearity in the range of 20-400 µg/L, with the correlation coefficient (r2) higher than 0.99. The limits of detection (LODs; S/N=3) and limits of quantification (LOQs; S/N=10) were found to be in the ranges of 0.1-1.0 µg/kg and 0.2-3.0 µg/kg, respectively. Furthermore, the results indicated that the average recoveries of the 11 sulfonamides ranged from 79.3% to 105.5% at three spiked levels of 50, 100, and 200 µg/kg, with the relative standard deviations (RSDs) in the range of 1.3%-11.6% (n=6). This method showed higher extraction efficiency than the one-step liquid-liquid extraction, and the detection sensitivity was highly improved.


Assuntos
Contaminação de Alimentos/análise , Carne Vermelha/análise , Sulfonamidas/análise , Animais , Cromatografia Líquida de Alta Pressão , Extração Líquido-Líquido , Extração em Fase Sólida , Suínos , Espectrometria de Massas em Tandem
4.
Se Pu ; 37(10): 1112-1117, 2019 Oct 08.
Artigo em Chinês | MEDLINE | ID: mdl-31642291

RESUMO

A method was developed for the simultaneous determination of 11 benzimildazoles residue markers in chicken meat, liver and kidney samples by high performance liquid chromatography (HPLC). The chicken tissue sample was extracted with acetonitrile, defatted with n-hexane, and purified with an MCX solid-phase extraction cartridge. Chromatographic separation was performed on an Atlantis T3 column with the gradient elution of methyl alcohol-1% (v/v) acetic acid aqueous solution as the mobile phases at a flow rate of 1.0 mL/min. The detection wavelength was set at 292 nm. Analytes were quantified by the external standard method. The linearities of the calibration curves were well in the range of 25-1000 µg/L, and the limit of quantification was 50 µg/kg. The recoveries at different spiked levels in all the three matrices ranged from 70.91% to 103.21%, and the relative standard deviations (RSDs) were between 1.48% and 10.08% (n=6). The developed method is characterized by an excellent purification effect, sensitivity and accuracy, and can be used for the determination of benzimidazoles residue markers in chicken tissue samples.


Assuntos
Benzimidazóis/análise , Contaminação de Alimentos/análise , Carne/análise , Animais , Galinhas , Cromatografia Líquida de Alta Pressão , Extração em Fase Sólida
5.
Se Pu ; 37(9): 946-954, 2019 Sep 08.
Artigo em Chinês | MEDLINE | ID: mdl-31642298

RESUMO

A method was established to rapidly determine 20 kinds of veterinary drug residues including three catagories of antibiotics (sulfonamides, quinolones, and chloramphenicols) and two kinds of triphenylmethanes (malachite green (MG) and leucomalachite green (LMG)) in fish and shrimp, based on dispersive solid phase extraction purification-ultra high performance liquid chromatography-tandem mass spectrometry. The samples were first hydrolyzed using a dipotassium hydrogen phosphate solution, and then extracted using acetonitrile. Afterward, the extraction solution was dehydrated and salted out with sodium chloride and condensed to nearly dry using a rotating evaporator. This residue was dissolved in 1.0 mL methanol. The resulting solution was purified by dispersive solid phase extraction method with C18 and PSA sorbents, and filtered through a filter. The target compounds were separated employing a ZORBAX C18 column. The mass spectrometer datas were acquired by multiple reaction monitoring (MRM) of positive and negative modes and quantitated applying the isotope internal standard method. The 20 veterinary drugs showed a good linear relationship in the range of 0.2-300 µg/L. The limits of detection and the limits of quantification were 0.1-0.6 and 0.3-1.8 µg/kg, respectively, while the correlation coefficients were greater than 0.99. The average recoveries at the three spiked levels (1, 5, and 20 times of quantitative limits) ranged between 72.5%-118%, with the relative standard deviations of 1.9%-9.8%. The advantages of method include a simple pretreatment, a high detection efficiency, and a low cost. Moreover, it is suitable for the simultaneous determination of multiple veterinary drug residues in fish and shrimp.


Assuntos
Resíduos de Drogas/análise , Alimentos Marinhos/análise , Drogas Veterinárias/análise , Animais , Antibacterianos/análise , Cromatografia Líquida de Alta Pressão , Extração em Fase Sólida , Espectrometria de Massas em Tandem , Compostos de Tritil/análise
6.
Se Pu ; 37(9): 990-995, 2019 Sep 08.
Artigo em Chinês | MEDLINE | ID: mdl-31642304

RESUMO

A rapid method based on ultra-performance convergence chromatography (UPC2) was developed for the analysis of 13 ultraviolet (UV) absorbents in plastic food contact materials. The UV absorbents were extracted from plastic food contact materials by supersonic extraction with methanol, purified by C18 solid phase extraction column, and analyzed via UPC2 before filtration with an organic filtration membrane (0.22 µm). An ACQUTY UPC2 HSS C18 SB chromatographic column (150 mm×3.0 mm, 1.8 µm) was used for the detection of the UV absorbents. An effective separation was achieved within 4 min under the optimized conditions. The mobile phases were supercritical carbon dioxide and isopropanol as a modifier. The results showed that the 13 UV absorbents exhibited good linear relationships in the respective linear ranges with the correlation coefficients no less than 0.9985. The limits of detection (S/N=3) were in the range of 0.05-0.15 mg/kg. The recoveries were from 86.8% to 115.7%, and the relative standard deviations were between 0.73% and 5.61%. This method is rapid, convenient, accurate and reliable, and can be used for the rapid determination of the 13 UV absorbents in plastic food contact materials.


Assuntos
Embalagem de Alimentos , Plásticos/análise , Cromatografia Líquida de Alta Pressão , Contaminação de Alimentos , Extração em Fase Sólida
7.
Se Pu ; 37(9): 1019-1025, 2019 Sep 08.
Artigo em Chinês | MEDLINE | ID: mdl-31642308

RESUMO

An analytical method for the determination of 34 pesticide residues in plant-derived foods was established using an automated QuEChERS sample preparation system combined with high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). The sample extraction and dispersive solid-phase extraction in the manual QuEChERS method were combined using the vortex vibration and centrifugation functions of the automated QuEChERS sample preparation system. The operating parameters and pretreatment steps were optimized, and the analytes were detected in the multiple reaction monitoring (MRM) mode. The quantification analysis was performed by the matrix-matched external standard method. The automated and the manual QuEChERS methods were compared from the methodological verification standpoint. The calibration curves showed good linearity in a certain range, and the correlation coefficients (R2) were greater than 0.99. The limits of detection and limits of quantification were 0.76-3.60 µg/kg and 2.28-10.80 µg/kg, respectively. Moreover, the recoveries ranged from 53.0% to 125.2%, and the relative standard deviations (RSDs) were less than 1.59% (n=5). The results obtained by the manual QuEChERS method were not significantly different from those obtained by the automated QuEChERS method. This method can effectively reduce the labor intensity and probability of error in the determination of pesticide residues.


Assuntos
Contaminação de Alimentos/análise , Resíduos de Praguicidas/análise , Verduras/química , Cromatografia Líquida de Alta Pressão , Extração em Fase Sólida , Espectrometria de Massas em Tandem
8.
J Agric Food Chem ; 67(40): 11236-11243, 2019 Oct 09.
Artigo em Inglês | MEDLINE | ID: mdl-31539244

RESUMO

A method for the simultaneous determination of 27 sulfonamides in poultry feathers using ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) was established in this study. The samples were extracted using 0.1 mol/L HCl solutions in a 60 °C water bath for 2 h, purified using hydrophilic-lipophilic balance solid-phase extraction, nitrogen-dried, and then reconstituted for UPLC-MS/MS analysis, which was performed with a CSH-C18 column. Linearity, limit of detection, limit of quantification, recovery, and precision were calculated in accordance with Commission Decision 2002/657/EC. For linearity, all standard curves showed a standard coefficient greater than 0.99, and the recoveries and coefficient of variation were 89-115% and <20%, respectively. The limit of detection and limit of quantification were 0.2-5 and 0.5-20 ng/g, respectively. The method was successfully applied to sulfamethazine (SMZ) residue accumulation monitoring in laying hen feathers and sulfonamide residue monitoring on poultry feathers. SMZ residue accumulation in the laying hen feathers was studied after administration with 100 mg/kg of SMZ for 21 consecutive days. SMZ residues were still detected in feathers 14 days after drug administration and persisted for up to 85 days. Results from 42 poultry feather samples showed that the feather is a suitable medium to monitor the illegal use of sulfonamides in poultry production.


Assuntos
Resíduos de Drogas/farmacocinética , Plumas/química , Sulfametazina/farmacocinética , Sulfonamidas/química , Animais , Galinhas/metabolismo , Cromatografia Líquida de Alta Pressão , Resíduos de Drogas/química , Resíduos de Drogas/isolamento & purificação , Resíduos de Drogas/metabolismo , Feminino , Limite de Detecção , Extração em Fase Sólida , Sulfametazina/química , Sulfametazina/isolamento & purificação , Sulfametazina/metabolismo , Sulfonamidas/isolamento & purificação , Sulfonamidas/metabolismo , Espectrometria de Massas em Tandem
9.
J Agric Food Chem ; 67(33): 9362-9370, 2019 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-31368700

RESUMO

This manuscript presents an effective and robust method for simultaneous stereoselective determination of two pyrethroid insecticides, tetramethrin and α-cypermethrin in different food products by high-performance liquid chromatography. Enantioseparation was carried out using reversed-phase chromatography, and the influences of four polysaccharide-based chiral columns, mobile phase composition, and column temperature on retention were fully investigated. Satisfactory separation was obtained on Chiralpak IG column using acetonitrile-water (75:25, v/v) under isocratic conditions. To extract and purify the target analytes from food matrices, matrix solid-phase dispersion was employed with C18 as dispersant and primary secondary amine as well as graphitized carbon black as cleanup sorbents. Response surface method based on Box-Behnken design was implemented to assist optimization of the extraction variables. Then, method validation was done in real samples including specificity, linearity, sensitivity, trueness, precision, as well as stability, and its analytical performance fulfills the criteria recommended by the European Union SANTE/11945/2015, demonstrating its applicability in studying the stereochemistry of chiral tetramethrin and α-cypermethrin in food products.


Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Grão Comestível/química , Frutas/química , Inseticidas/química , Piretrinas/química , Verduras/química , Cromatografia de Fase Reversa/métodos , Contaminação de Alimentos/análise , Inseticidas/isolamento & purificação , Piretrinas/isolamento & purificação , Extração em Fase Sólida , Estereoisomerismo
10.
J Forensic Leg Med ; 67: 28-36, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31398663

RESUMO

The application of forensic entomotoxicology in investigations of death by poisoning has gained popularity as insects serves as an alternative specimen (evidence) when conventional toxicological samples have degraded or are no longer available. Successful detection, identification, and quantification of drugs and toxic substances from insects have been demonstrated through various research experiments. In the present review paper, role of insects as toxicological sample, its collection and preservation, analysis using various instrumental techniques, and trends in the use of analytical techniques have been discussed. Limitations hindering the growth of this field and the way forward for future studies have been highlighted. In addition, the effect of poisons on insects used for postmortem interval estimation has been described.


Assuntos
Entomologia , Comportamento Alimentar , Toxicologia Forense/métodos , Envenenamento/diagnóstico , Mudanças Depois da Morte , Animais , Depressores do Sistema Nervoso Central/análise , Besouros , Dípteros , Etanol/análise , Humanos , Larva , Extração Líquido-Líquido , Praguicidas/análise , Preparações Farmacêuticas/análise , Extração em Fase Sólida , Xenobióticos
11.
J Environ Manage ; 249: 109415, 2019 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-31445375

RESUMO

The solid phase extraction method has been developed and applied for the simultaneous analysis of the five most commonly used triazine pesticides. The analysis was conducted using a liquid chromatography-photodiode array detector, which was first optimized to improve the limit of quantification and detection. The extraction parameters (conditioning solvent and sample volume) that affect the recovery of the analytes for solid phase extraction were optimized. The recoveries obtained were between 107 and 111%. The limit of detection ranged between 0.668 and 1.16 µg/L and the limit of quantification ranged between 2.01 and 3.54 µg/L. Good precision with a relative standard deviation of less than 8% in all compounds was achieved. The developed and validated method was then applied to river water, wastewater and sludge samples from around KwaZulu-Natal. The quantified concentrations ranged from 8.35 to 2820 µg/L, 2.41-48.7 µg/L and 3.20-65.0 µg/L in sludge, wastewater, and river water respectively.


Assuntos
Herbicidas , Poluentes Químicos da Água , Cromatografia Líquida de Alta Pressão , Limite de Detecção , Esgotos , Extração em Fase Sólida , África do Sul , Triazinas , Água
12.
Anal Bioanal Chem ; 411(23): 6189-6202, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31414155

RESUMO

It is a challenge to expand the metabolome coverage of liquid chromatography (LC)-electrospray ionization (ESI) mass spectrometry (MS) based untargeted metabolomics analysis. The limited coverage is attributed to the weak signal of hydroxyl and carboxyl groups in ESI-MS and the limited capacity of LC separation for metabolites with a wide range of polarities. Here a new sample preparation procedure is proposed to solve these problems. Mixed-mode (reversed-phase and anion-exchange) solid-phase extraction sorbents were used to separate metabolites into hydrophilic amine, hydrophobic amine/alcohol, and organic acid groups. Then, alcohols and carboxylic acids in separated groups were tagged with pyridine with use of two derivatization systems for signal enhancement. Finally, hydrophilic amines were analyzed by LC-MS with a hydrophilic interaction LC column, and the two hydrophobic compound groups were analyzed by LC-MS with a C18 column. From the results for standard samples, the detection limits of the new method are lower than those of the classic solvent extraction-protein precipitation method by 3.3-70 times for five amino acids and by 65-1141 times for five fatty acids. Moreover, the detection limit of this new method is 125 ng mL-1 for cholesterol, which has no signal with the classic method even at 10 µg mL-1. In seminal plasma samples, 110 more metabolites were identified by this new method than by the traditional solvent extraction-protein precipitation method in positive-mode ESI (new method vs traditional method, 65 vs 22 identified by comparing MS/MS spectra with those of standards, 203 vs 136 identified by searching MS spectra in a published database). Among them, 53 carboxylic acids and 21 alcohols were identified only by the new method, and more hydrophilic amine metabolites, such as amino acids and nucleosides, were identified by the new method than by the classic method. Finally, in application to the study of male infertility, more potential biomarkers of oligoasthenoteratospermic infertility were found with the new method (46 potential biomarkers) than with the classic method (19 potential biomarkers) and previously reported methods (10-30 potential biomarkers). Thus, it is demonstrated that this new sample preparation method expands the detection coverage of LC-MS-based untargeted metabolomics methods and has application potential in biological research.


Assuntos
Infertilidade Masculina/metabolismo , Metaboloma , Metabolômica/métodos , Sêmen/metabolismo , Biomarcadores/metabolismo , Humanos , Masculino , Sêmen/química , Extração em Fase Sólida/métodos , Espectrometria de Massas por Ionização por Electrospray/métodos
13.
Food Chem ; 298: 125066, 2019 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-31261009

RESUMO

A ultrasensitive chemiluminescence (CL) method for the determination of fluoroquinolones (FQs) in milk was proposed based on the enhancement effect of FQs on the CL reaction between cerium(IV) and methoxylated Cypridina luciferin analogs (MCLA). Prior to the CL determination, molecularly imprinted polymers (MIPs) with superior recognition performances were adopted to the clean-up and extraction of the family of FQs. Then the developed CL system coupling with MIPs (MIP-CL) was applied to the selective determination of FQs in milk. Under the optimized conditions, the method was validated with respect to linearity, precision, accuracy, limits of detection and quantification. The relative standard deviation (RSD) on intra-day assay was below 5.1%, and detection limit was as low as 0.10 nmol/L. The consistency of this method and HPLC method was compared and validated by the paired t-test. The results indicated that the proposed method allowed class-specific determination of FQs in complex matrices.


Assuntos
Fluoroquinolonas/análise , Medições Luminescentes/métodos , Impressão Molecular/métodos , Polímeros/química , Animais , Cério/química , Fluoroquinolonas/isolamento & purificação , Limite de Detecção , Leite/química , Extração em Fase Sólida
14.
J Agric Food Chem ; 67(28): 8035-8044, 2019 Jul 17.
Artigo em Inglês | MEDLINE | ID: mdl-31282154

RESUMO

The simultaneous detection of multiple mycotoxins is important due to the increased toxic effects of combined mycotoxins in grains. In this research, a combination of modified QuEChERS with ultrahigh-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) was used for simultaneous detection of 20 mycotoxins in grains. A series of different types of magnetic (Fe3O4) nanoparticles modified with multiwalled carbon nanotubes (Fe3O4-MWCNTs) were designed as modified QuEChERS adsorbents for facile and efficient purification and for target interferences removal in the matrices. When there is an external magnetic field, the proposed modified QuEChERS method uses a shorter pretreatment time compared with the traditional QuEChERS method, which makes it possible to conduct high-throughput analyses. To optimize the QuEChERS process, the extraction solvent and the type and amount of the Fe3O4-MWCNTs were investigated. Under optimal conditions, the method was validated and showed satisfactory linearity (r2 ≥ 0.9965), good recovery (73.5-112.9%), good precision (1.3-12.7%), and excellent sensitivity (ranging from 0.0021 to 5.4457 ng g-1), which indicates that this method can be used for detecting multiple mycotoxins in real samples.


Assuntos
Carbono/química , Cromatografia Líquida de Alta Pressão/métodos , Grão Comestível/química , Micotoxinas/química , Micotoxinas/isolamento & purificação , Nanotubos/química , Extração em Fase Sólida/métodos , Espectrometria de Massas em Tandem/métodos , Adsorção , Magnetismo , Extração em Fase Sólida/instrumentação
15.
J Chromatogr A ; 1602: 350-358, 2019 Sep 27.
Artigo em Inglês | MEDLINE | ID: mdl-31257039

RESUMO

This work describes development of a quick and accurate online solid-phase extraction (SPE) liquid chromatography tandem mass spectrometry method for simultaneous determination of 87 emerging organic compounds, including 22 per- and polyfluoroalkyl substances, 58 pharmaceuticals and personal care products, and 7 organophosphorus flame retardants, in diverse water matrices. Considering the wide range of physicochemical properties for the target contaminants, efficient analysis in one injection is challenging. Thus, key extraction and analytical parameters, including online SPE sorbent, mobile phase additives, sample pH, loading solvent pH and composition, injection volume, and valve-switching time, were systematically optimized. The final conditions, namely a polymeric reversed-phase column with alkaline samples and an acidic loading solvent, provided satisfactory results for all target analytes compared to conventional methods that employ acidic samples for multi-residue analysis. The method detection limits (MDLs) ranged from 0.16 to 5.13 ng L-1 with 85% of MDLs lower than 2 ng L-1 for sample volumes of just 1.8 mL. The method also demonstrated satisfactory accuracy with 82% of analytes exhibiting 70-130% recovery. Importantly, only 30 min was required per sample. The optimized method was successfully applied to investigate the removal efficiency of emerging contaminants in a drinking water treatment plant and to analyze the environmental occurrence of target analytes. The method is sensitive, reliable, labor-saving, and cost effective, and therefore has the potential to advance large-scale environmental monitoring programs.


Assuntos
Cromatografia Líquida/métodos , Retardadores de Chama/análise , Fluorcarbonetos/análise , Produtos Domésticos/análise , Preparações Farmacêuticas/análise , Extração em Fase Sólida/métodos , Espectrometria de Massas em Tandem/métodos , Poluentes Químicos da Água/análise , Automação , Monitoramento Ambiental , Concentração de Íons de Hidrogênio , Internet , Limite de Detecção , Solventes/química , Fatores de Tempo
16.
Food Chem ; 300: 125204, 2019 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-31336275

RESUMO

Analytical chromatographic techniques for mycotoxins control are well established, but they often depend on costly immunoaffinity sample clean-up. Serum albumins, particularly that from bovine origin (BSA), have stable binding affinity towards some mycotoxins, and can be cheaper alternative receptors for sample clean-up due to their wide availability. Thus, this work used BSA immobilized in agarose beads as a novel solid-phase extraction method for quantification of ochratoxin A (OTA) in wine. Constructed BSA-agarose columns could extract OTA efficiently from red wine after its dilution (4-fold) in 0.1 M Tris pH 8.0. The method was linear (R2 = 0.9999) in the OTA concentration range studied (0.05 to 3.0 µg L-1), with recovery rates above 98%. It also showed low detection (0.017 µg L-1) and quantification (0.051 µg L-1) limits. The efficacy of the BSA-based method was further validated by direct comparison with commercial immunoaffinity columns. Portuguese wines analyzed by both methods had agreeing results.


Assuntos
Contaminação de Alimentos/análise , Ocratoxinas/análise , Soroalbumina Bovina/química , Extração em Fase Sólida/métodos , Vinho/análise , Cromatografia Líquida de Alta Pressão/métodos , Concentração de Íons de Hidrogênio , Limite de Detecção , Micotoxinas/análise , Reprodutibilidade dos Testes , Extração em Fase Sólida/instrumentação
17.
J Food Sci ; 84(7): 1992-2002, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31264718

RESUMO

A simple, fast, and efficient method, "enhanced matrix removal of lipids" (EMR-lipid), was proposed, optimized, and validated for identifying five polar heterocyclic amines (HCAs) in meat samples that ranged from high-protein (beef and chicken) to high-fat (pork bacon) matrices. The protocol involves an initial solid-liquid phase extraction followed by a rapid dispersive solid-phase extraction using EMR-lipid sorbents and salting-out partitioning. Acetonitrile containing formic acid at two levels (1% and 2%) efficiently extracted HCAs from different meat matrices. Liquid chromatography-tandem mass spectrometry (MS/MS) with selective reaction monitoring mode was developed for qualitative and quantitative analysis. The highest MS/MS responses and better peak separation of analytes were achieved by adjusting mobile phases to pH 3.0 with instrumental detection limits between 0.01 and 0.05 ng/mL. Good linearity of standard curves was obtained in both pure solvents and postspiked meat extracts between 0.5 and 50.0 ng/mL. The validation results showed good precision, accuracy, and sensitivity for detecting HCAs in spiked meat samples. Satisfactory recoveries of four HCAs were achieved: 65% to 111% in beef, 71% to 106% in bacon, and 42% to 77% in chicken. Matrix effects were also assessed and showed less than -20% of ion suppression in bacon extract, while a medium to high signal suppression was observed in beef (-37% to -55%) and chicken (-28% to -52%). This optimized EMR-lipid method provides acceptable results and advantages for determining trace level HCAs in complex meat matrices.


Assuntos
Aminas/análise , Aminas/isolamento & purificação , Cromatografia Líquida de Alta Pressão/métodos , Extração Líquido-Líquido/métodos , Carne/análise , Extração em Fase Sólida/métodos , Espectrometria de Massas em Tandem/métodos , Animais , Bovinos , Galinhas , Contaminação de Alimentos/análise , Suínos
18.
Anal Chim Acta ; 1078: 78-89, 2019 Oct 31.
Artigo em Inglês | MEDLINE | ID: mdl-31358231

RESUMO

Based on a one-step combustion fabrication approach, a novel magnetic porous carbon (MPC) was fabricated using filter paper as porous carbon source and iron salts as magnetic precursors. The textural properties of the MPC were characterized by transmission electron microscopy (TEM), Fourier transform infrared spectrometry (FT-IR), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), vibration sample magnetometer (VSM) and nitrogen absorption-desorption isotherms. The as-prepared MPC possessed a high specific surface area, a microstructure comprised of mesopores and strong magnetic response. It was employed as a magnetic solid-phase extraction (MSPE) adsorbent for the determination of three non-steroidal anti-inflammatory drugs (NSAIDs) in environmental water and biological samples coupled with high performance liquid chromatography (HPLC). The main parameters affecting extraction efficiency were investigated in detail and a satisfactory performance was obtained under the optimal conditions. The calibration curves were linear over the concentration ranging from 1 to 1200 µg L-1 for ketoprofen (KET) and 2-1200 µg L-1 for naproxen (NAP) and diclofenac (DCF) with determination coefficients (R2) between 0.9995 and 0.9997. The limits of detection (LODs) were in the range of 0.2-0.4 µg L-1. The intra- and inter-day relative standard deviations (RSDs) were less than 4.03% and 8.72%, respectively. The recoveries ranged from 84.67% to 113.73% with RSDs less than 7.76%. The satisfactory results confirmed the great potential of the novel MPC adsorbent for the extraction of NSAIDs from complex sample matrices.


Assuntos
Anti-Inflamatórios não Esteroides/análise , Carbono/química , Diclofenaco/análise , Cetoprofeno/análise , Naproxeno/análise , Adsorção , Anti-Inflamatórios não Esteroides/sangue , Anti-Inflamatórios não Esteroides/urina , Diclofenaco/sangue , Diclofenaco/urina , Química Verde/métodos , Cetoprofeno/sangue , Cetoprofeno/urina , Limite de Detecção , Nanopartículas de Magnetita/química , Naproxeno/sangue , Naproxeno/urina , Porosidade , Rios/química , Extração em Fase Sólida/instrumentação , Extração em Fase Sólida/métodos , Poluentes Químicos da Água/análise
19.
Fa Yi Xue Za Zhi ; 35(3): 344-348, 2019 Jun.
Artigo em Inglês, Chinês | MEDLINE | ID: mdl-31282633

RESUMO

Abstract: Currently, the main sample pretreatment methods for forensic toxic analysis are liquid-liquid extraction (LLE) and solid-phase extraction (SPE). As a simple, convenient, and low-cost LLE method, dispersion liquid-liquid microextraction (DLLME) has high enrichment factor and good extraction efficiency, and therefore has attracted the attention of many researchers in the field of toxicology analysis in recent years. As a multi-functional microextraction method, DLLME has been widely used in the analysis of pesticides, sleeping sedatives, drugs and heavy metal poisons in forensic toxic analysis. Meanwhile, it can also be used in combination with such a variety of analytical instruments as gas chromatography-electron capture detectors (GC-ECD), high performance liquid chromatography-diode array detectors (HPLC-DAD). As a sample pretreatment method, DLLME has the advantages of simple operation, less use of organic solvent, reliable results and good reproducibility, thus can meet the requirements of modern court toxic analysis.


Assuntos
Microextração em Fase Líquida , Toxicologia Forense , Reprodutibilidade dos Testes , Extração em Fase Sólida , Solventes
20.
J Chromatogr A ; 1602: 178-187, 2019 Sep 27.
Artigo em Inglês | MEDLINE | ID: mdl-31301797

RESUMO

A magnetic porous covalent triazine-based organic polymer (M-PCTP) was synthesized by co-precipitation method. The M-PCTP combined both the properties of the PCTP and the magnetism of Fe3O4 nanoparticles, possessing highly porous structure and good magnetism. It was used as a magnetic solid phase extraction (MSPE) adsorbent to extract carbamate pesticides (propoxur, carbaryl, isoprocarb, fenobcarb and diethofencarb) from lemonade and grape juice samples prior to high performance liquid chromatography-mass spectrometric detection. Under the optimal conditions, a good linearity for the real samples was received in the range from 0.10-0.90 to 80.00 ng mL-1 with the correlation coefficients of 0.9882-0.9983. The method recoveries for the five carbamates were 86.3-108.0%. The limits of detection were 0.02-0.20 ng mL-1 for lemonade sample, and 0.04-0.30 ng mL-1 for grape juice sample. The M-PCTP also demonstrated good extraction capabilities for other different kinds of organic compounds including chlorophenols and polycyclic aromatic hydrocarbons.


Assuntos
Carbamatos/isolamento & purificação , Cromatografia Líquida de Alta Pressão , Análise de Alimentos/métodos , Espectrometria de Massas , Praguicidas/análise , Extração em Fase Sólida , Sucos de Frutas e Vegetais/análise , Magnetismo , Hidrocarbonetos Policíclicos Aromáticos/análise , Polímeros/química , Porosidade
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