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1.
J Chromatogr A ; 1525: 161-172, 2017 Nov 24.
Artigo em Inglês | MEDLINE | ID: mdl-29056272

RESUMO

In the present study, a quick and sensitive method was developed for simultaneous determination of nonylphenol ethoxylates (NPxEOs) and octylphenol ethoxylates (OPxEOs) (x=2-20) in three leafy vegetables, including cabbage, lettuce, and spinach using a modified "QuEChERS" method and ultra-high performance supercritical fluid chromatography-tandem mass spectrometry (UHPSFC-MS/MS) with scheduled multiple reaction monitoring (MRM). Under optimized conditions, the 38 target analytes were analyzed within a short period of time (5 min). The linearities of the matrix-matched standard calibrations were satisfactory with coefficients of determination (R2)>0.99 and the limits of detection (LOD) and quantification (LOQ) were in between 0.02-0.27 and 0.18-1.75µgkg-1, respectively. The recovery of all target analytes spiked at three (low, medium, and high) fortification levels in various leafy vegetables were ranged from 72.8-122.6% with relative standard deviation (RSD) ≤18.3%. The method was successfully applied to market samples and the target analytes were found in all monitored samples, with total concentrations of 0-8.67µgkg-1 and 15.75-95.75µgkg-1 for OPxEOs and NPxEOs (x=2-20), respectively. In conclusion, the newly developed UHPSFC-ESI-MS/MS method is rapid and versatile and could be extrapolated for qualitative and quantitative analysis of APxEOs in other leafy vegetables.


Assuntos
Cromatografia com Fluido Supercrítico , Análise de Alimentos/métodos , Fenóis/análise , Espectrometria de Massas em Tandem , Verduras/química , Poluentes Ambientais/análise , Limite de Detecção
2.
Artigo em Inglês | MEDLINE | ID: mdl-27187439

RESUMO

Nonylphenol (NP) was quantified using liquid chromatography tandem mass spectrometry (LC-MS/MS) in the urine and plasma of rats treated with 0, 50, and 250 mg/kg/day of NP for four consecutive days. A urinary metabolomic strategy was originally implemented by high performance liquid chromatography time of flight mass spectrometry (HPLC-QTOF-MS) to explore the toxicological effects of NP and determine the overall alterations in the metabolite profiles so as to find potential biomarkers. It is essential to point out that from the observation, the metabolic data were clearly clustered and separated for the three groups. To further identify differentiated metabolites, multivariate analysis, including principal component analysis (PCA), orthogonal partial least-squares discriminant analysis (OPLS-DA), high-resolution MS/MS analysis, as well as searches of Metlin and Massbank databases, were conducted on a series of metabolites between the control and dose groups. Finally, five metabolites, including glycine, glycerophosphocholine, 5-hydroxytryptamine, malonaldehyde (showing an upward trend), and tryptophan (showing a downward trend), were identified as the potential urinary biomarkers of NP-induced toxicity. In order to validate the reliability of these potential biomarkers, an independent validation was performed by using the multiple reaction monitoring (MRM)-based targeted approach. The oxidative stress reflected by urinary 8-oxo-deoxyguanosine (8-oxodG) levels was elevated in individuals highly exposed to NP, supporting the hypothesis that mitochondrial dysfunction was a result of xenoestrogen accumulation. This study reveals a promising approach to find biomarkers to assist researchers in monitoring NP.


Assuntos
Fenóis/toxicidade , 8-Hidroxi-2'-Desoxiguanosina , Animais , Biomarcadores/sangue , Biomarcadores/urina , Cromatografia Líquida de Alta Pressão/métodos , Desoxiguanosina/análogos & derivados , Desoxiguanosina/urina , Análise Discriminante , Feminino , Glicerilfosforilcolina/urina , Glicina/urina , Análise dos Mínimos Quadrados , Malondialdeído/urina , Espectrometria de Massas/métodos , Metabolômica , Análise Multivariada , Estresse Oxidativo/efeitos dos fármacos , Análise de Componente Principal , Ratos Sprague-Dawley , Reprodutibilidade dos Testes , Serotonina/urina , Triptofano/urina
3.
J Chromatogr B Analyt Technol Biomed Life Sci ; 878(23): 2047-53, 2010 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-20598653

RESUMO

A novel method based on the molecularly imprinted solid-phase extraction (MISPE) procedure has been developed for the simultaneous determination of concentrations of sulfonylurea herbicides such as chlorsulfuron (CS), monosulfuron (MNS), and thifensulfuron methyl (TFM) in maize samples by liquid chromatography-tandem quadrupole mass spectrometry (LC-MS/MS). The molecularly imprinted polymer (MIP) for sulfonylurea herbicides was synthesized by precipitation polymerization using chlorsulfuron as the template molecule, 2-(diethylamino)ethyl methacrylate (DEAMA) as the functional monomer, and trimethylolpropane trimethacrylate (TRIM) as the cross-linker. The selectivities of the chlorsulfuron template and its analogs on the molecularly imprinted polymer were evaluated by high-performance liquid chromatography (HPLC). The extraction and purification procedures for the solid-phase extraction (SPE) cartridge with a molecularly imprinted polymer as the adsorbent for the selected sulfonylurea herbicides were then established. A molecularly imprinted solid-phase extraction method followed by high-performance liquid chromatography-tandem mass spectrometry for the determination of chlorsulfuron, monosulfuron, and thifensulfuron methyl was also established. The mean recoveries of these compounds in maize were in the range 75-110% and the limits of detection (LOD) of chlorsulfuron, monosulfuron, and thifensulfuron methyl were 0.02, 0.75, and 1.45 microg kg(-1), respectively. It was demonstrated that the MISPE-HPLC-MS/MS method could be applied to the determination of chlorsulfuron, monosulfuron, and thifensulfuron methyl in maize samples.


Assuntos
Monitoramento Ambiental/métodos , Herbicidas/análise , Impressão Molecular/métodos , Polímeros/química , Compostos de Sulfonilureia/análise , Espectrometria de Massas em Tandem/métodos , Zea mays/química , Cromatografia Líquida de Alta Pressão , Herbicidas/química , Microscopia Eletrônica de Varredura , Compostos de Sulfonilureia/química
4.
Guang Pu Xue Yu Guang Pu Fen Xi ; 30(11): 3052-5, 2010 Nov.
Artigo em Chinês | MEDLINE | ID: mdl-21284182

RESUMO

A novel class-specific molecularly imprinted polymer (MIP) beads for sulfonylurea herbicides was synthesized by precipitation polymerization using chlorsulfuron as the template molecule, 2-(diethylamino) ethyl methacrylate (DEAEMA) as the functional monomer, and trimethylolpropane trimethacrylate (TRIM) as the cross-linker. The mechanisms of recognition of MIP beads to the template molecule were evaluated by UV-spectrum and FTIR in the choosing and optimizing polymerization system experiment. The results showed that MIP beads contained the group which could interact with template molecule and its analogue by the hydrogen bonding specifically.

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