Quechers Method
Mostrando 13-24 de 46 artigos, teses e dissertações.
-
13. Determination of Pesticides in Grape Juices by QuEChERS and Liquid Chromatography-Tandem Mass Spectrometry
In this study, we describe a liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for quantifying 25 pesticides in grape juice. This method was optimized and validated according with INMETRO (Instituto Nacional de Metrologia Qualidade e Tecnologia) for the simultaneous determination of pesticide, which are widely used in grape culture in Brazil.
J. Braz. Chem. Soc.. Publicado em: 2016-09
-
14. Evaluation of QuEChERS Sample Preparation and Gas Chromatography Coupled to Mass Spectrometry for the Determination of Pesticide Residues in Grapes
An effective analytical method for pesticides multiresidue determination in grape samples was developed and validated. A modified quick, easy, cheap, effective, robust and safe (QuEChERS) method was used to extract the target compounds. Several sorbent materials were tested for the clean-up step using dispersive solid phase extraction (d-SPE) and Florisil®
J. Braz. Chem. Soc.. Publicado em: 2016-09
-
15. Application of a 33 Box-Behnken Design to Optimize the Extraction of Eleven Fluoroquinolones from Poultry Muscle and Kidney Using a QuEChERS Approach via Liquid Chromatography Tandem Mass Spectrometry: the Easy Use of Microsoft Excel® in Multivariate Analysis
This work presents an optimization of a quick, easy, cheap, effective, rugged and safe (QuEChERS) extraction approach of eleven fluoroquinolones in poultry muscle and kidney using a 33 Box-Behnken factorial design. All the data treatment was performed using Microsoft Excel® 2010. The suitability of the developed method was confirmed by two proficiency tests
J. Braz. Chem. Soc.. Publicado em: 2016-01
-
16. Simultaneous Determination of Herbicides in Rice by QuEChERS and LC-MS/MS Using Matrix-Matched Calibration
The main objective of the present work was to validate a chromatographic method to determine herbicides commonly applied in the irrigated rice farming. For this, matrix-matched calibration was employed along with the extraction and clean-up of the samples by quick, easy, cheap, effective, rugged and safe (QuEChERS) method and determination of the analytes by
J. Braz. Chem. Soc.. Publicado em: 2016-01
-
17. Effects of Types of Washing and Peeling in Relation to Pesticide Residues in Tomatoes
Tomatoes are widely consumed and most often without cooking, therefore it is important to estimate the reduction of residues using simple washing procedures. An experiment was carried out to evaluate the effects of household processing such as: washing with water, washing with 10% of vinegar solution and washing with 10% of sodium bicarbonate solution on pes
J. Braz. Chem. Soc.. Publicado em: 2015-10
-
18. EVALUATION OF A BUFFERED SOLID PHASE DISPERSION PROCEDURE ADAPTED FOR PESTICIDE ANALYSES IN THE SOIL MATRIX
An evaluation of the pesticides extracted from the soil matrix was conducted using a citrate-buffered solid phase dispersion sample preparation method (QuEChERS). The identification and quantitation of pesticide compounds was performed using gas chromatography-mass spectrometry. Because of the occurrence of the matrix effect in 87% of the analyzed pesticides
Quím. Nova. Publicado em: 2015-08
-
19. PESTICIDE RESIDUES IN CONVENTIONALLY AND ORGANICALLY GROWN TOMATOES IN ESPÍRITO SANTO (BRAZIL)
The aim of this study was to investigate the presence of acephate, carbaryl, carbendazim, chlorpyrifos, dichlorvos, fenpropathrin, methamidophos and permethrin in conventionally and organically grown tomatoes from Espírito Santo, Brazil, between May 2012 and April 2013. QuEChERS sample preparation was used and analysis was performed by LC-MS/MS and GC-MS
Quím. Nova. Publicado em: 2015-07
-
20. MONITORAMENTO DE RESÍDUOS DE AGROTÓXICOS DA CLASSE DOS ORGANOFOSFORADOS POR CGDFC EM AMOSTRAS DE LEITE FLUÍDO E EM PÓ
Samples of whole fluid pasteurized, UHT and powdered milk were analyzed for the presence of organophosphorus pesticide residues (OPR) using the QuEChERS method with detection by GC-FPD and confirmation by UPLC-MS/MS. A total of 23% of fluid milk samples and 27% of powdered milk samples contained at least one organophosphorus residue. The OPR found in the sam
Quím. Nova. Publicado em: 2015-02
-
21. Multivariate optimization of the QuEChERS-GC-ECD method and pesticide investigation residues in apples, strawberries, and tomatoes produced in Brazilian south
Culturas como maçã, morango e tomate estão entre os alimentos de maior contaminação por uso de pesticidas no Brasil. Pensando nisso, a otimização multivariada do método QuEChERS, acoplado ao CG-ECD, foi proposta a fim de investigar os níveis de resíduos dos pesticidas clorpirifós, dimetoato, malationa, mevinfós, pedimentalina, simazina e triflura
J. Braz. Chem. Soc.. Publicado em: 2014-09
-
22. Multiresidue determination of pesticide residues in honey by modified QuEChERS method and gas chromatography with electron capture detection
O mel pode apresentar resíduos de pesticidas devido à contaminação das abelhas durante a coleta de pólen e néctar ou por tratamento das colmeias. Assim, a determinação de resíduos de pesticidas em mel é de grande importância, apesar da dificuldade devido à complexidade da matriz. Neste estudo, um novo método para a determinação de pesticidas d
J. Braz. Chem. Soc.. Publicado em: 2014-08
-
23. Determinação de resíduos de agrotóxicos em leite bovino empregando método QuEChERS modificado e GC-MS/MS
Considering the possibility that pesticides used in cattle raising produce residues in milk and cause harm to public health, this study developed a multiresidue method for determination of pesticide residues in bovine milk, using a modified QuEChERS method for sample preparation, and quantification by GC-MS/MS. The method proved to be efficient, resulting in
Quím. Nova. Publicado em: 2014-06
-
24. Optimization of chromatographic conditions and comparison of extraction efficiencies of four different methods for determination and quantification of pesticide content in bovine milk by UFLC-MS/MS
This paper describes the optimization of a multiresidue chromatographic analysis for the identification and quantification of 20 pesticides in bovine milk, including three carbamates, a carbamate oxime, six organophosphates, two strobilurins, a pyrethroid, an oxazolidinedione, an aryloxyphenoxypropionate acid/ester, a neonicotinoid, a dicarboximide, and thre
Quím. Nova. Publicado em: 2014