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2.
Environ Pollut ; : 115121, 2020 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-33139099

RESUMO

Polybrominated dibenzo-p-dioxins and dibenzofurans (PBDD/Fs), as the secondary environmental pollutants of the widely used brominated flame retardants (BFRs), possess the similar physicochemical and toxic properties as polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs). However, studies on human body exposure to them are extremely limited. In this study, forty human milk samples collected in Shanghai were measured for 13 PBDD/F congeners using gas chromatography-high resolution mass spectrometry (GC-HRMS), to investigate their exposure level and characteristics, potential source and corresponding health risks to breastfed infants. The results showed no PBDDs but three PBDF congeners including 2,3,7,8-TBDF, 1,2,3,4,6,7,8-HpBDF and OBDF (mean concentration (detection rates) are 3.2 pg/g (72.5%), 9.5 pg/g (100%) and 28 pg/g (67.5%), respectively) were detected. The average toxic equivalent quantity (TEQ, 0.42 pg/g lw) presented the highest concentration level compared to other regions reported. The contribution of PBDFs to the total TEQ of PBDD/Fs and PCDD/Fs is 6.8%. The correlation between PBDD/Fs and age or dietary habits was not observed, which normally existed in their chlorinated analogues-PCDD/Fs. Significant correlations were observed between PBDFs and highly brominated polybrominated diphenyl ethers (PBDEs) (especially for BDE 183 and BDE 209). The correlation between PCDD/Fs and PBDFs was not observed except 2,3,7,8-TBDF. The high PBDFs exposure in Shanghai may originate from the emission of PBDEs and/or non-PBDE BFRs in environment, according to the consistency of the environmental data previously reported. The average estimated dietary intakes (EDI) for breastfed infants is 2.0 pg TEQ/kg·bw/day (0.13-13 pg TEQ/kg·bw/day), within the range of the tolerable daily intake (TDI) for TCDD (1-4 pg TEQ/kg·bw/day) suggested by the World Health Organization (WHO). However, given the high toxicity of PBDD/Fs, the potential health risks of these pollutants for breastfed infants should be of concern.

3.
Food Chem ; 320: 126576, 2020 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-32200175

RESUMO

A rapid and high-throughput method using both GC-MS/MS and UPLC-Q-Orbitrap systems was applied for pesticide multi-residues analysis in food samples. Strategies based on QuEChERs extraction, intelligent data mining tools with in-house/online database, and in-silico fragment prediction system were introduced to screen and identify target/untargeted features. Full-scan combined with data-independent-acquisition modes was evaluated in real sample in an attempt to improve and facilitate the pesticide screening process, of which the results showed that FS-vDIA provided equal detection rate (100%) and far less false positive results than FS-AIF did. The proposed methodology was evaluated in analysis of pesticide multi-residues in several proficiency test samples provided by EURL, and exhibited a high detection rate (>90%) of various pesticide residues with satisfactory recoveries (70-130%) without reporting false positive results. The method was also applied in China's national surveys from 2016 to 2019, and results showed its high performance in pesticide analysis in different food matrices.


Assuntos
Análise de Alimentos/métodos , Contaminação de Alimentos/análise , Resíduos de Praguicidas/análise , Cromatografia Gasosa/métodos , Cromatografia Líquida de Alta Pressão/métodos , Simulação por Computador , Frutas/química , Espectrometria de Massas em Tandem/métodos , Verduras/química
4.
Chemosphere ; 271: 129447, 2020 Dec 27.
Artigo em Inglês | MEDLINE | ID: mdl-33476874

RESUMO

Computational QSAR models have gradually been preferred for retention time prediction in data mining of emerging environmental contaminants using liquid chromatography coupled with mass spectrometry. Generally, the model performance relies on the components such as machine learning algorithms, chemical features, and example data. In this study, we evaluated the performances of four algorithms on three feature sets, using 321 and 77 pesticides as the training and validation sets, respectively. The results were varied with different combinations of algorithms on distinct feature sets. Two strategies including enhancing the complexity of chemical features and enlarging the size of the training set were proved to improve the results. XGBoost, Random Forest, and lightGBM algorithms exhibited the best results when built on a large-scale chemical descriptors, while the Keras algorithm preferred fingerprints. These four models have comparable prediction accuracies that at least 90% of pesticides in validation set can be successfully predicted with ΔRT <1.0 min. Meanwhile, a blended prediction strategy using average results from four models presented a better result than any single model. This strategy was used for assisting identification of pesticides and pesticide transformation products in 120 strawberry samples from a national survey of food contamination. Twenty pesticides and twelve pesticide transformation products were tentatively identified, where all pesticides and two pesticide transformation products (bifenazate diazene and spirotetramat-enol) were confirmed by standard materials. The outcome of this study suggested that retention time prediction is a valuable approach in compound identification when integrated with in silico MS2 spectra and other MS identification strategies.

5.
Wei Sheng Yan Jiu ; 47(6): 924-928, 2018 Nov.
Artigo em Chinês | MEDLINE | ID: mdl-30593321

RESUMO

OBJECTIVE: To investigate the pollution level of dioxin-like compounds in animal-derived foods from 10 cities of Shaanxi Province. METHODS: Collect four representative food samples( pork, beef, fish and eggs) to determine the concentrations of29 types of dioxin-like compounds by high-resolution gas chromatographs/high-resolution mass spectrometers( HRGC-HRMS). RESULTS: The result showed that the toxic equivalent quantity( TEQ) value of dioxin-like compounds in fish was 0. 085 pg TEQ/g, which was the biggest among the 4 food samples. The TEQ values for pork, beef and eggs were 0. 049, 0. 034 and 0. 040 pg TEQ/g, respectively. The TEQ values of dioxin-like compounds were higher in the fish meat of Ankang and the pork of Hanzhoung, but were lower than the max limit of commission regulation European Union. The total dietary intake of the above four foods was 2. 01 pg/( kg·BW·month), which was much lower than the provisional tolerable monthly intake( PTMI) of Joint FAO/WHO Expert Committee on Food Additives 70 pg/( kg·BW·month). CONCLUSION: The residents in the 10 cities of Shaanxi Province are at a low health risk caused by the intake of dioxin-like compounds.


Assuntos
Dioxinas , Ovos , Contaminação de Alimentos , Carne , Bifenilos Policlorados , Animais , Benzofuranos , Bovinos , China , Dioxinas/análise , Poluentes Ambientais , Bifenilos Policlorados/análise , Dibenzodioxinas Policloradas
6.
Anal Bioanal Chem ; 409(22): 5307-5317, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-28741109

RESUMO

Commonly, analytical methods measuring brominated flame retardants (BFRs) of different chemical polarities in human serum are labor consuming and tedious. Our study used acidified diatomaceous earth as solid-phase extraction (SPE) adsorbent and defatting material to simultaneously determine the most abundant BFRs and their metabolites with different polarities in human serum samples. The analytes include three types of commercial BFRs, tetrabromobisphenol A (TBBPA), hexabromocyclododecane (HBCD) isomers, and polybrominated biphenyl ethers (PBDEs), and dominant hydroxylated BDE (OH-PBDE) and methoxylated BDE (MeO-PBDE) metabolites of PBDEs. The sample eluents were sequentially analyzed for PBDEs and MeO-BDEs on online gel permeation chromatography/gas chromatography-electron capture-negative ionization mass spectrometry (online GPC GC-ECNI-MS) and for TBBPA, HBCD, and OH-BDEs on liquid chromatography-tandem mass spectrometry (LC-MS/MS). Method recoveries were 67-134% with a relative standard deviation (RSD) of less than 20%. Method detection limits (MDLs) were 0.30-4.20 pg/mL fresh weight (f.w.) for all analytes, except for BDE-209 of 16 pg/mL f.w. The methodology was also applied in a pilot study, which analyzed ten real samples from healthy donors in China, and the majority of target analytes were detected with a detection rate of more than 80%. To our knowledge, it is the first time for us in effectively determining BFRs of most types in one aliquot of human serum samples. This new analytical method is more specific, sensitive, accurate, and time saving for routine biomonitoring of these BFRs and for integrated assessment of health risk of BFR exposure.


Assuntos
Análise Química do Sangue/métodos , Retardadores de Chama/análise , Éteres Difenil Halogenados/sangue , Compostos de Bromo/análise , Éteres Difenil Halogenados/metabolismo , Humanos , Limite de Detecção , Controle de Qualidade , Extração em Fase Sólida , Fatores de Tempo
7.
Anal Bioanal Chem ; 408(18): 4897-906, 2016 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-27178547

RESUMO

An improved method based on tandem solid phase extraction (SPE) cleanup and gas chromatography-high resolution mass spectrometry (GC-HRMS) has been validated for a rapid determination of dibenzo-p-dioxins/furans (PCDD/Fs), dioxin-like polychlorinated biphenyls (PCBs), marker polychlorinated biphenyls (M-PCBs), and polybrominated diphenyl ethers (PBDEs) using a large volume (50 mL) of human milk. This method was well validated for the measurement of these analytes in human milk from the general population with low limits of detection (LODs, 0.004-0.12 ng/g lipid), satisfactory accuracy (75-120 % of recoveries), and precision [less than 10 % of relative standard deviations (RSDs)]. To comprehensively evaluate the performance of this method, a good, presently validated and routinely used method based on an automated sample clean-up system (ASCS, based on the commercial acid multilayer silica, basic alumina, and carbon columns) was used in parallel for comparison. Compared with the ASCS method, this method presented comparable specificity. Additionally, this method, in contrast to ASCS method, highly reduced consumption of solvents (40 mL versus 500 mL), which results in much lower background in the procedural blank, reduced time, and enhanced sample pretreatment throughput. This method was also applied in a pilot study to measure a batch of human milk samples with satisfactory results. Graphical Abstract Characteristics of the application of tandem SPE cleanup for determination of PCDD/Fs, DL-PCBs,M-PCBs and PBDEs in human milk.


Assuntos
Poluentes Ambientais/análise , Análise de Alimentos/métodos , Contaminação de Alimentos/análise , Hidrocarbonetos Aromáticos/análise , Leite/química , Extração em Fase Sólida/métodos , Espectrometria de Massas em Tandem/métodos , Animais , Humanos , Hidrocarbonetos Aromáticos/química , Bifenilos Policlorados , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Manejo de Espécimes/métodos
8.
J Chromatogr A ; 1445: 80-92, 2016 May 06.
Artigo em Inglês | MEDLINE | ID: mdl-27063369

RESUMO

It is of great interest to develop strategic methods to enable chemicals' metabolites to be accurately and rapidly screened and identified. To screen and identify a category of metabolites with distinct isotopic distribution, this study proposed a generic strategy using in silico metabolite prediction plus accurate-mass-based isotopic pattern recognition (AMBIPR) and library identification on the data acquired via the data dependent MS/MS scan of LC-Q Exactive Orbitrap mass spectrometry. The proposed method was evaluated by the analysis of flurochloridone (FLC) metabolites in rat urine sample collected from toxicity tests. Different from the traditional isotopic pattern recognition (IPR) approach, AMBIPR here was performed based on the potential metabolites predicted via in silico metabolite prediction tools. Thus, the AMBIPR treated FLC data was only associated with FLC metabolites, consequently not only avoiding great efforts made to remove FLC-unrelated information and reveal FLC metabolites, but also increasing the percent of positive hits. Among the FLC metabolite peaks screened using AMBIPR, 87% of them (corresponding 97 metabolites and 49 biotransformation) were successfully identified via multiple MS identification techniques packaged in an established FLC's metabolites library based on Mass Frontier. Noteworthy, 34 metabolites (89%) were identified without distinct naturally isotopic distribution. The universal strategic approach based on background subtraction (BS) and mass defect filtering (MDF) was used to evaluate the AMBIPR and no more false positive and negative metabolites were detected. Furthermore, our results revealed that AMBIPR is very effective, inherently sensitive and accurate, and is easily automated for the rapidly screening and profiling chemicals related metabolites.


Assuntos
Cromatografia Líquida , Pirrolidinonas/química , Pirrolidinonas/urina , Espectrometria de Massas em Tandem , Urinálise/métodos , Animais , Biotransformação , Masculino , Pirrolidinonas/metabolismo , Ratos
9.
Artigo em Inglês | MEDLINE | ID: mdl-27085014

RESUMO

Bromophenols (BrPs), as the metabolites of PBDEs, would be the potential exposure markers for human biomonitoring (HB) of PBDEs in urine. An analytical method using solid-phrase extraction (SPE) and gas chromatography coupled to tandem mass spectrometer (GC-MS/MS) was developed and validated for simultaneous determination of nineteen BrPs in human urine. The method detection limits (MDLs) were below 23pgmL(-1), with recovery ranged from 63% to 133% and inter-day repeatability ranged from 3% to 11% for the majority of target analytes. This method was applied in a pilot study and 2-Bromophenol (2-BrP), 4-Bromophenol (4-BrP), 2,4-Dibromophenol (2,4-DBP) and 2,4,6-Tribromophenol (2,4,6-TBP) as the predominant analytes were detected in human urine samples collected from the general population. Among the four detected analytes, 2-BrP and 4-BrP as the mono-brominated BrP congeners were firstly reported. To our knowledge, it is the first study covering all BrP congeners (from mono-brominated to penta-brominated, totally 19 congeners) in human urine. Therefore, this study is very useful for profiling urinary BrPs and discovering potential relationship between urinary BrPs and human internal exposure to PBDEs. The mechanism of fragmentation pathway of silanized BrPs was firstly illustrated in this study.


Assuntos
Biomarcadores/urina , Exposição Ambiental/análise , Cromatografia Gasosa-Espectrometria de Massas/métodos , Éteres Difenil Halogenados/urina , Fenóis/urina , Espectrometria de Massas em Tandem/métodos , Biomarcadores/química , Éteres Difenil Halogenados/química , Humanos , Limite de Detecção , Modelos Lineares , Fenóis/química , Reprodutibilidade dos Testes
10.
Can J Physiol Pharmacol ; 94(1): 28-34, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26394869

RESUMO

Rosiglitazone, which is mainly used in the treatment of diabetes mellitus, is also involved in the regulation of inflammation. The peroxisome proliferator-activated receptor (PPAR)-γ receptor subtype appears to play a pivotal role in the regulation of inflammation. However, the exact mechanism for the protective effects of rosiglitazone against inflammation such as liver injury remains unclear. The aim of this study was to investigate the effects of rosiglitazone on inflammation in the liver of rats treated with D-GaIN/LPS. Male Sprague-Dawley rats were injected with D-GaIN/LPS with or without pre-administration of rosiglitazone (3, 10, or 30 mg/kg, intraperitoneal injection). Our data showed that rosiglitazone significantly inhibited D-GaIN/LPS-induced hepatotoxicity in a dose-dependent manner, as indicated by both diagnostic indicators of liver damage (serum aminotransferase activities) and histopathological analysis. Western blot analysis showed that rosiglitazone significantly decreased protein expression levels of COX-2 and production of pro-inflammatory markers, including TNF-α and IL-6, in D-GaIN/LPS-treated rat liver. The results indicated that the inhibition of D-GaIN/LPS-induced inflammation by rosiglitazone can be attributed, at least partially, to its capacity to regulate the the immunoregulatory transcription factor nuclear factor kappa B (NF-κB) signaling pathway.


Assuntos
Doença Hepática Induzida por Substâncias e Drogas/prevenção & controle , NF-kappa B/metabolismo , Tiazolidinedionas/farmacologia , Alanina Transaminase/sangue , Animais , Aspartato Aminotransferases/sangue , Doença Hepática Induzida por Substâncias e Drogas/metabolismo , Doença Hepática Induzida por Substâncias e Drogas/patologia , Ciclo-Oxigenase 2/metabolismo , Modelos Animais de Doenças , Mediadores da Inflamação/metabolismo , Interleucina-6/metabolismo , Masculino , Substâncias Protetoras/farmacologia , Ratos , Ratos Sprague-Dawley , Rosiglitazona , Transdução de Sinais/efeitos dos fármacos , Fator de Necrose Tumoral alfa/metabolismo
11.
Drug Dev Ind Pharm ; 42(2): 280-7, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-26165244

RESUMO

OBJECTIVE: The main objective of this study was to develop and evaluate a W/O microemulsion formulation of troxerutin to improve its oral bioavailability. METHODS: The W/O microemulsion was optimized using a pseudo-ternary phase diagram and evaluated for physical properties. In vitro MDCK cell permeability studies were carried out to evaluate the permeability enhancement effect of microemulsion, and in vivo absorption of troxerutin microemulsion in the intestine was compared with that of solution after single-dose administration (56.7 mg/kg) in male Wistar rats. RESULTS: The optimal formulation consisted of lecithin, ethanol, isopropyl myristate and water (23.30/11.67/52.45/12.59 w/w) was physicochemical stable and the mean droplet size was about 50.20 nm. In vitro study, the troxerutin-loaded microemulsion showed higher intestinal membrane permeability across MDCK monolayer when compared with the control solution. The W/O microemulsion can significantly promote the intestinal absorption of troxerutin in rats in vivo, and the relative bioavailability of the microemulsion was about 205.55% compared to control solution. CONCLUSION: These results suggest that novel W/O microemulsion could be used as an effective formulation for improving the oral bioavailability of troxerutin.


Assuntos
Anticoagulantes/administração & dosagem , Sistemas de Liberação de Medicamentos , Hidroxietilrutosídeo/análogos & derivados , Administração Oral , Animais , Anticoagulantes/farmacocinética , Disponibilidade Biológica , Permeabilidade da Membrana Celular , Química Farmacêutica/métodos , Cães , Composição de Medicamentos/métodos , Estabilidade de Medicamentos , Emulsões , Hidroxietilrutosídeo/administração & dosagem , Hidroxietilrutosídeo/farmacocinética , Absorção Intestinal , Células Madin Darby de Rim Canino , Masculino , Tamanho da Partícula , Permeabilidade , Ratos , Ratos Wistar , Água/química
12.
Chemosphere ; 137: 14-24, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-25966445

RESUMO

Human milk samples were collected from 150 mothers in 2011 and 2012 in Shanghai, China and analyzed for 17 polychlorinated dibenzo-p-dioxins/furans (PCDD/Fs) and 12 dioxin-like polychlorinated biphenyls (DL-PCBs). The up-bound Toxic Equivalent Quantity (TEQ) ranged from 0.27 to 16.8 pg TEQ/g lipid (mean 5.4 pg TEQ/g lipid) for ∑PCDD/Fs and from 0.75 to 10.2 pg TEQ/g lipid (mean 2.9 pg TEQ/g lipid) for ∑DL-PCBs. TEQs in our study were lower than those in most countries worldwide, and displayed a notable uptrend, in contrast with those in China's national survey in 2007. TEQs in mother milks from urban areas were higher than those from rural areas, and an orderly distribution was found in four geographical regions: Eastern China>Central China≈Southwestern China>Northwestern China. Levels of analytes in Shanghai native mothers' milk ranked the first among those from all provinces and cities investigated. Migrant mothers to Shanghai from other inland provinces could potentially represent the population for exposure and risk assessment in their birth and grown-up places. Both the distribution and the uptrend were associated with release of these pollutants due to rapid industrialization and urbanization in China. Fine correlations were observed between TEQs and age of mothers, and weak correlations between TEQs and consumption of meat & meat products. Participants, who preferred both fresh water and marine fish to freshwater fish only, were prone to be exposed to higher level of PCBs. The estimated daily intake (EDI) doses for breastfed neonates entirely exceeded the tolerable intake dose by WHO.


Assuntos
Benzofuranos/análise , Monitoramento Ambiental/estatística & dados numéricos , Poluentes Ambientais/análise , Leite Humano/química , Bifenilos Policlorados/análise , Dibenzodioxinas Policloradas/análogos & derivados , Polímeros/análise , Adolescente , Adulto , Animais , Aleitamento Materno , China , Feminino , Peixes , Humanos , Recém-Nascido , Masculino , Mães , Dibenzodioxinas Policloradas/análise , Medição de Risco , Fatores de Tempo , Adulto Jovem
13.
Anal Bioanal Chem ; 407(14): 4131-41, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-25903021

RESUMO

This study developed a new method for the analysis of 20 phenolic compounds in human urine. The urine samples were prepared by hydrochloric acid (HCl) hydrolysis, liquid-liquid extraction (LLE), and solid-phase extraction (SPE) cleanup. We found that HCl hydrolysis is of similar effectiveness to, and much cheaper than, the traditional enzymatic method. Vanillic acid was co-eluted with butyl paraben and interfered with the determination of butyl paraben in urine. K2CO3-treated-silica-gel SPE was designed to efficiently eliminate interference from the endogenous organic acids (especially vanillic acid) in urine. After derivatization, the samples were analyzed by large-volume-injection gas chromatography-tandem mass spectrometry (LVI-GC-MS-MS). Good linearity (R (2) ≥ 0.996) was established in the range 0.1-100 ng mL(-1) for all analytes. Method detection limits (MDLs) were 0.7-9.8 pg mL(-1). Intraday (n = 5) and interday (n = 5 days) validation was performed, with satisfactory accuracy (recovery: 70-126 % and 73-107 %, respectively) and precision (RSD ≤ 19 %) at two levels (low: 0.1 and 0.5 ng mL(-1); high: 5 and 10 ng mL(-1)). The method was used in a population study and achieved more than 85 % detection for most analytes; mean analyte concentrations were in the range 0.01-185 ng mL(-1). The method is suitable for the analysis of multiple phenolic metabolites in human urine.


Assuntos
Carbonatos/química , Cromatografia Gasosa/métodos , Ácido Clorídrico/química , Fenóis/urina , Potássio/química , Dióxido de Silício/química , Extração em Fase Sólida/métodos , Adulto , Pré-Escolar , Humanos , Hidrólise , Lactente , Reprodutibilidade dos Testes , Espectrometria de Massas em Tandem/métodos
14.
Environ Sci Pollut Res Int ; 22(12): 9293-306, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25595932

RESUMO

Organochlorine pesticides (OCPs) are persistent organic pollutants that could cause deleterious effects on human health. Breast milk represents a noninvasive specimen source to assess maternal and infant exposure to OCPs. This study recruited 142 pregnant mothers in 2011-2012 in Shanghai, China, and their breast milk samples were collected during lactation and analyzed for 27 OCP compounds. Detection rates were in a range of 65.5 to 100 %. In particular, metabolites of 2,2-bis(chlorophenyl)-1,1,1-trichloroethane (DDT) such as 2-chloro-1,1-bis(4-chlorophenyl)ethylene (DDMU), 2,2-bis(4-chlorophenyl)ethanol (DDOH), bis(4-chlorophenyl)ketone (DBP), and 4,4'-dichlorodiphenylmethane (DDM) were detected in most milk samples. DDTs, hexachlorobenzene (HCB), and hexachlorocyclohexane (HCH) were dominant OCPs with mean levels of 316, 49.8, and 41.5 ng/g lipid content, respectively, whereas levels of methoxychlor, ∑Drins, ∑Heptachlor, ∑Chlordane, and ∑Endosulfan were fairly low (0.87-5.6 ng/g lipid content). Milk concentrations of OCPs were weakly correlated with maternal age, body weight, and body mass indexes (BMIs). ∑OCPs in this study were much lower than those in human breast milk samples collected in 2002 and 2007. Consumption of higher amounts of fish was associated with higher milk levels of OCPs. Specific OCP patterns in breast milk samples from migrant mothers in Shanghai reflected features of OCP production, use, and exposure in their home provinces. The probabilistic exposure assessment model reveals that Shanghai infants were exposed to low levels of OCPs through breast milk consumption. However, infants as the vulnerable group might be subject to the potential additive and/or synergistic health effects from complex OCP exposure.


Assuntos
Hidrocarbonetos Clorados/química , Leite Humano/química , Praguicidas/química , China , Feminino , Humanos , Hidrocarbonetos Clorados/metabolismo , Masculino , Praguicidas/metabolismo , Gravidez
15.
Chemosphere ; 114: 327-36, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25113219

RESUMO

A novel method was developed for the analysis of organochlorine pesticides (OCPs), polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs) in human hair samples. External contaminants of hair were extracted with acetone under sonication, while washed hair was further hydrolyzed in formic acid and acetone (1:4, v/v) with microwave assisted extraction (MAE) for internal contaminant measurements. Both internal and external extracts were cleaned up with gel permeation chromatography (GPC) and then solid phase extraction (SPE), before analyzed by a large volume injection-gas chromatography-tandem mass spectrometry (LVI-GC-MS/MS) using triple quadruple mass analyzer. Good linearity (R(2)⩾ 0.996) was established within a concentration range between 0.1 and 100 ng mL(-)(1) among all target analytes. The method was validated for accuracy, precision and sensitivity. The developed method is intended to be cost effective and robust for the routine human hair analysis of PCBs, PBDEs and OCPs including acid-labile OCPs. The described method has been applied in pilot biomonitoring study and the preliminary data suggested that the contaminant profiles with the use of partial least-squares analysis discriminant analysis (PLA-DA) could be useful in differentiating external and internal exposure.


Assuntos
Monitoramento Ambiental/métodos , Poluentes Ambientais/análise , Cabelo/química , Éteres Difenil Halogenados/análise , Praguicidas/análise , Bifenilos Policlorados/análise , Formiatos/química , Cromatografia Gasosa-Espectrometria de Massas/métodos , Humanos , Hidrólise , Limite de Detecção , Extração em Fase Sólida/métodos , Espectrometria de Massas em Tandem/métodos
16.
Artigo em Inglês | MEDLINE | ID: mdl-24321764

RESUMO

A new method was developed to determine polybrominated diphenyl ethers (PBDEs) and polychlorinated biphenyls (PCBs) in fishery and aquaculture products. Samples were extracted by an accelerated solvent extraction system and cleaned up by sequential solid phase extraction (SPE) including dispersive SPE (D-SPE) and tandem SPE. PBDEs and PCBs were analyzed by a large-volume injection gas chromatography triple quadrupole mass spectrometry (LVI-GC-QqQ-MS/MS). Good linearity (R(2)≥0.9958) was achieved. Method detection limits (MDLs) were 0.16-3.3pgg(-1) (wet weight, ww) for PBDEs and 0.13-0.97pgg(-1)ww for PCBs. Mean recoveries were 60-140% with relative standard deviations (RSDs) of less than 20% in weever fish, scallop and shrimp samples spiked at a lower level of 13-31pgg(-1)ww and a higher level of 50-125pgg(-1)ww. Certified reference materials were analyzed with acceptable results. The method reduced solvent consumption, analytical time and labor, and is suitable for the routine analysis of PBDEs and PCBs in fishery and aquaculture products.


Assuntos
Produtos Pesqueiros/análise , Éteres Difenil Halogenados/análise , Análise de Perigos e Pontos Críticos de Controle/métodos , Bifenilos Policlorados/análise , Extração em Fase Sólida/métodos , Poluentes Químicos da Água/análise , Animais , Pesqueiros/métodos , Peixes , Limite de Detecção , Espectrometria de Massas em Tandem/métodos
17.
Environ Int ; 60: 137-44, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-24056321

RESUMO

Pyrethroid insecticides have been applied in the production of cotton, wool and textile. In order to examine whether textile workers are exposed to pyrethroid insecticides, we recruited 50 textile workers in two textile plants in Eastern China. Their urine samples were collected for the measurement of pyrethroid metabolites: cis- and trans-isomers of 2,2-dichlorovinyl-2,2-dimethylcyclopropane-1-carboxylic acid (cis-Cl2CA and trans-Cl2CA) and 3-phenoxybenzoic acid (3-PBA). Our results showed that textile workers were exposed to high levels of pyrethroid insecticides. cis-Cl2CA and 3-PBA were dominant metabolites with concentrations of 0.17-261µg/L, while concentrations of trans-Cl2CA were in the range of 0.26-11µg/L. Levels of three metabolites were in a descending order: cis-Cl2CA, 3-PBA, and trans-Cl2CA. Levels of the metabolites were associated with ages and job responsibilities of textile workers. Sewing workers, cutting workers, machine operators, reorganizers, and older workers were more likely in contact with pyrethroid insecticides in the textile production. trans- to cis-Cl2CA ratios might indicate that exposure of textile workers was via dermal absorption and inhalation.


Assuntos
Monitoramento Ambiental/métodos , Inseticidas/urina , Exposição Ocupacional/análise , Piretrinas/urina , Indústria Têxtil , Adolescente , Adulto , China , Feminino , Humanos , Inseticidas/química , Inseticidas/metabolismo , Isomerismo , Masculino , Pessoa de Meia-Idade , Piretrinas/química , Piretrinas/metabolismo , Têxteis , Adulto Jovem
18.
Artigo em Inglês | MEDLINE | ID: mdl-22476052

RESUMO

In this study, a method was developed to determine 45 selected pesticides (of different chemical families) in fruit and vegetable (including apple, spinach and cucumber). Samples were extracted using an improved QuEChERS method with salting out and phase separation in two steps. The target pesticides in concentrated extracts were analyzed by an on-line gel permeation chromatography-gas chromatography/mass spectrometer (online-GPC-GC/MS). Online GPC effectively removed matrix interferences and greatly improved the method sensitivity, recoveries and automation. Method limits of quantification were 10 ng/g for uniconazole and metalaxyl, and 5 ng/g for other 43 target analytes. In three fruit and vegetable matrices each spiked with 45 pesticides (0.01 µg/g), mean recoveries ranged from 80 to 118% for most of the tested pesticides except for profenofos (77% in apple) and chlorpyrifos (68% in apple and 75% in cucumber), with relative standard deviations (RSDs) of less than 14%. The results of the proficiency testing showed that the method is very successful in measuring the certified pesticides with less than 1.3 of the absolute value of Z-score. This method has been applied for routinely monitoring pesticides in fresh fruit and vegetable.


Assuntos
Cromatografia em Gel/métodos , Frutas/química , Cromatografia Gasosa-Espectrometria de Massas/métodos , Resíduos de Praguicidas/análise , Verduras/química , Acetatos , Fracionamento Químico , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
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