Efeito de componentes da matriz na análise de agrotóxicos por cromatografia gasosa

Detalhes bibliográficos
Autor(a) principal: Pinho, Gevany Paulino de
Data de Publicação: 2009
Tipo de documento: Tese
Idioma: por
Título da fonte: LOCUS Repositório Institucional da UFV
Texto Completo: http://locus.ufv.br/handle/123456789/206
Resumo: This work aimed to systematically study the matrix effect on the measurement of pesticides chlorpyrifos, λ−cyhalothrin, cypermethrin and deltamethrin by gas chromatography with electron capture detector. The matrix effect is attributed to the presence of co-extractives in the organic phase during extraction. In this work, the phenomenon matrix effect is described in detail in a review discussing qualitative and quantitative aspects as well as techniques used to minimize it. Also reports results that quantify co-extractive interference with the chromatographic response of the four pesticides. There was a positive matrix effect after GC saturation with multiple injections of tomato organic extracts for the four pesticides. It was also found that the longer the retention time, the greater the matrix effect (10% for chlorpyrifos, 103% for λ-cyhalothrin, 162% for cypermethrin and 300% for deltamethrin), and that the internal standard minimizes the effect, but not eliminate it. An in-depth study of chlorpyrifos and deltamethrin adsorption on the injector and chromatography column was carried out. These were the pesticides that showed the lowest and greatest matrix effect, respectively, in previous studies. The capacity of chlorpyrifos and deltamethrin being adsorbed in the injector and chromatography column was assessed by plotting three isotherms with the injector at 310, 280 and 250°C and modifying the heating rate of the column to 10 and 30 °C min-1. For a range of concentrations between 5 and 500 µg L-1, the results showed that the higher the injector temperature (310 ° C) and the lower the heating rate of the chromatography column (10 °C min-1), the lower is the pesticide adsorption in the chromatography system. The results also showed that deltamethrin may present characteristics of protective analyte, reducing chlorpyrifos adsorption in the analysis of analyte standard solutions in pure solvent. A simple and practical method for identification and quantification of chlorpyrifos, λ-cyhalothrin, deltamethrin and cypermethrin in honey samples was also optimized and validated. The method is based on liquid-liquid extraction and purification at low temperature using the extractor mixture acetonitrile:ethyl acetate (6.5 mL: 1.5 mL). An additional clean-up step was performed with 2.0 g of florisil before analysis by gas chromatography. The efficiency of the technique was shown to be satisfactory (> 85%) and chromatographic response was linear for all pesticides in the range 0033 - 0.17 µg g-1, with correlation coefficients above 0.99. Limits of detection and quantification were below 0.017 and 0033 µg g-1 respectively. The proposed method was applied to 11 honey samples and detected residues of chlorpyrifos and λ-cyhalothrin in two samples, at concentrations below the MRLs established for food products. The presence of these compounds was confirmed by mass spectrometry in the SIM mode (GC-MS-SIM). Finally, the influence of chemical constituents of nine matrices (honey, tomatoes, milk, apples, soil, potatoes, liver, rump meat and water) on the quantification of the pesticides by GC-ECD was studied. With this purpose, organic extracts of each matrix were obtained from LLE-LTP or SLE-LTP and used to saturate the chromatography system. Standard pesticide solutions were injected before and after GC saturation with extracts of each matrix. Variation of chromatographic responses was evaluated by principal component analysis (PCA) and hierarchical cluster analysis (HCA). Results showed that the constituents of tomato organic extracts accounted for the greatest matrix effect on pyrethroid chromatographic responses in GC-ECD analyses (100 to 300%). This was confirmed by principal component analysis, which evaluated the distance of the response of tomato organic extracts from the other responses. Furthermore, the saturation of the chromatography system with extracts of water, soil, apple and honey decreased pyrethroid chromatographic responses.
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spelling Pinho, Gevany Paulino dehttp://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4131534A6Reis, Césarhttp://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4785327P6Queiroz, Maria Eliana Lopes Ribeiro dehttp://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4781671U3Neves, Antônio Augustohttp://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4788868U1Collins, Carol Hollingworthhttp://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4787830U1Coutrim, Maurício Xavierhttp://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4785465J72015-03-26T12:05:55Z2009-08-132015-03-26T12:05:55Z2009-04-24PINHO, Gevany Paulino de. Effect of components of the matrix in pesticide analysis by gas chromatography. 2009. 120 f. Tese (Doutorado em Agroquímica analítica; Agroquímica inorgânica e Físico-química; Agroquímica orgânica) - Universidade Federal de Viçosa, Viçosa, 2009.http://locus.ufv.br/handle/123456789/206This work aimed to systematically study the matrix effect on the measurement of pesticides chlorpyrifos, λ−cyhalothrin, cypermethrin and deltamethrin by gas chromatography with electron capture detector. The matrix effect is attributed to the presence of co-extractives in the organic phase during extraction. In this work, the phenomenon matrix effect is described in detail in a review discussing qualitative and quantitative aspects as well as techniques used to minimize it. Also reports results that quantify co-extractive interference with the chromatographic response of the four pesticides. There was a positive matrix effect after GC saturation with multiple injections of tomato organic extracts for the four pesticides. It was also found that the longer the retention time, the greater the matrix effect (10% for chlorpyrifos, 103% for λ-cyhalothrin, 162% for cypermethrin and 300% for deltamethrin), and that the internal standard minimizes the effect, but not eliminate it. An in-depth study of chlorpyrifos and deltamethrin adsorption on the injector and chromatography column was carried out. These were the pesticides that showed the lowest and greatest matrix effect, respectively, in previous studies. The capacity of chlorpyrifos and deltamethrin being adsorbed in the injector and chromatography column was assessed by plotting three isotherms with the injector at 310, 280 and 250°C and modifying the heating rate of the column to 10 and 30 °C min-1. For a range of concentrations between 5 and 500 µg L-1, the results showed that the higher the injector temperature (310 ° C) and the lower the heating rate of the chromatography column (10 °C min-1), the lower is the pesticide adsorption in the chromatography system. The results also showed that deltamethrin may present characteristics of protective analyte, reducing chlorpyrifos adsorption in the analysis of analyte standard solutions in pure solvent. A simple and practical method for identification and quantification of chlorpyrifos, λ-cyhalothrin, deltamethrin and cypermethrin in honey samples was also optimized and validated. The method is based on liquid-liquid extraction and purification at low temperature using the extractor mixture acetonitrile:ethyl acetate (6.5 mL: 1.5 mL). An additional clean-up step was performed with 2.0 g of florisil before analysis by gas chromatography. The efficiency of the technique was shown to be satisfactory (> 85%) and chromatographic response was linear for all pesticides in the range 0033 - 0.17 µg g-1, with correlation coefficients above 0.99. Limits of detection and quantification were below 0.017 and 0033 µg g-1 respectively. The proposed method was applied to 11 honey samples and detected residues of chlorpyrifos and λ-cyhalothrin in two samples, at concentrations below the MRLs established for food products. The presence of these compounds was confirmed by mass spectrometry in the SIM mode (GC-MS-SIM). Finally, the influence of chemical constituents of nine matrices (honey, tomatoes, milk, apples, soil, potatoes, liver, rump meat and water) on the quantification of the pesticides by GC-ECD was studied. With this purpose, organic extracts of each matrix were obtained from LLE-LTP or SLE-LTP and used to saturate the chromatography system. Standard pesticide solutions were injected before and after GC saturation with extracts of each matrix. Variation of chromatographic responses was evaluated by principal component analysis (PCA) and hierarchical cluster analysis (HCA). Results showed that the constituents of tomato organic extracts accounted for the greatest matrix effect on pyrethroid chromatographic responses in GC-ECD analyses (100 to 300%). This was confirmed by principal component analysis, which evaluated the distance of the response of tomato organic extracts from the other responses. Furthermore, the saturation of the chromatography system with extracts of water, soil, apple and honey decreased pyrethroid chromatographic responses.O presente trabalho teve como objetivo estudar sistematicamente o efeito de matriz na quantificação dos agrotóxicos clorpirifós, λ-cialotrina, cipermetrina e deltametrina durante análises por cromatografia gasosa com detector por captura de elétrons. O efeito de matriz é atribuído à presença de coextrativos na fase orgânica obtida no processo de extração. Neste trabalho, o fenômeno efeito de matriz , é descrito em detalhes numa revisão que aborda os aspectos qualitativos e quantitativos do mesmo bem como as técnicas utilizadas para minimizá-lo. São relatados também alguns resultados que quantificam a interferência dos coextrativos na resposta cromatográfica para os quatro agrotóxicos. Observou-se para esses compostos um efeito de matriz positivo após a saturação do CG com várias injeções de extratos orgânicos de tomate. Verificou-se também que quanto maior o tempo de retenção, maior o efeito de matriz (clorpirifós: 10%, λ-cialotrina :103% e cipermetrina: 162%; deltametrina: 300% ), e que o uso do padrão interno minimiza o efeito, mas não o elimina. Um estudo detalhado da adsorção de clorpirifós e deltametrina no injetor e coluna cromatográfica foi realizado. Estes agrotóxicos foram os que apresentaram menor e maior efeito de matriz, respectivamente, nos estudos prévios. A capacidade dos agrotóxicos clorpirifós e deltametrina serem adsorvidos no injetor e na coluna cromatográfica foi avaliada construindo-se três isotermas com o injetor em 310, 280 e 250 °C, modificando a taxa de aquecimento da coluna para 10 e 30 °C min-1, para uma faixa de concentração dos agrotóxicos entre 5 e 500 µg L-1. Os resultados mostraram que quanto maior a temperatura do injetor (310 °C) e menor taxa de aquecimento da coluna cromatográfica (10 °C min-1) menor é a adsorção dos agrotóxicos no sistema cromatográfico. Os resultados também mostraram que a deltametrina pode apresentar características de analito protetor, diminuindo a adsorção do clorpirifós nas análises de soluções padrão destes analitos em solvente puro. Um método simples e prático para identificação e quantificação do clorpirifós, λ-cialotrina, cipermetrina e deltametrina em amostras de mel também foi otimizado e validado. O método se baseia na extração líquido-líquido e purificação em baixa temperatura utilizando como mistura extratora acetonitrila:acetato de etila (6,5 mL:1,5 mL). Uma etapa adicional de clean up foi realizada com 2,0 g de florisil antes da análise por cromatografia gasosa. A técnica mostrou-se com eficiência satisfatória (> 85%) e a resposta cromatográfica foi linear, para os quatro agrotóxicos, na faixa de 0,033 0,17 µg g-1, com coeficientes de correlação superiores a 0,99. Os limites de detecção e quantificação foram inferiores a 0,017 e 0,033 µg g-1, respectivamente. O método proposto foi aplicado em 11 amostras de mel sendo detectados resíduos de clorpirifós e λ-cialotrina em duas amostras, em concentrações próximas ao limite máximo de resíduo estabelecido para produtos alimentícios. A presença destes compostos foi confirmada por espectrometria de massas com monitoramento de íons selecionados (CG-EMMIS). Finalmente, estudou-se a influência dos constituintes químicos de nove matrizes (mel, tomate, leite, maçã, solo, batata, fígado, alcatra e água) na quantificação dos quatro agrotóxicos por CG-DCE. Para isso, extratos orgânicos de cada matriz foram obtidos a partir da ELL-PBT ou ESL-PBT e, posteriormente, utilizados para saturar o sistema cromatográfico. Solução padrão dos agrotóxicos foi injetada antes e após a saturação do CG com extratos de cada matriz. A variação da resposta cromatográfica foi avaliada utilizando análises das componentes principais (ACP) e análises hierárquicas de agrupamentos (AHA). Os resultados mostraram que os constituintes de extratos orgânicos de tomate foram os responsáveis pelo maior efeito de matriz nas respostas cromatográficas dos piretroides em análises por CG- DCE (100 a 300%). Isso foi verificado pela análise das componentes principais, avaliando o distanciamento da resposta obtida para o extrato orgânico das amostras de tomate das demais respostas. Além disso, a saturação do sistema cromatográfico com extratos de água, solo, maçã e mel diminuíram a resposta cromatográfica dos piretroides.Fundação de Amparo a Pesquisa do Estado de Minas Geraisapplication/pdfporUniversidade Federal de ViçosaDoutorado em AgroquímicaUFVBRAgroquímica analítica; Agroquímica inorgânica e Físico-química; Agroquímica orgânicaEfeito de matrizAgrotóxicosCromatografia gasosaMatrix effectPesticidesGas chromatographyCNPQ::CIENCIAS EXATAS E DA TERRA::QUIMICA::QUIMICA ANALITICAEfeito de componentes da matriz na análise de agrotóxicos por cromatografia gasosaEffect of components of the matrix in pesticide analysis by gas chromatographyinfo:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/doctoralThesisinfo:eu-repo/semantics/openAccessreponame:LOCUS Repositório Institucional da UFVinstname:Universidade Federal de Viçosa (UFV)instacron:UFVORIGINALtexto completo.pdfapplication/pdf987820https://locus.ufv.br//bitstream/123456789/206/1/texto%20completo.pdf5077e6a544d92a8ead441711fd3b1544MD51TEXTtexto completo.pdf.txttexto completo.pdf.txtExtracted texttext/plain189651https://locus.ufv.br//bitstream/123456789/206/2/texto%20completo.pdf.txt0e6dd9a5b62b37adab9ac5db6b50e094MD52THUMBNAILtexto completo.pdf.jpgtexto completo.pdf.jpgIM Thumbnailimage/jpeg3879https://locus.ufv.br//bitstream/123456789/206/3/texto%20completo.pdf.jpge834b12a2ab0b80cd35a4fb821b771b1MD53123456789/2062016-04-06 08:00:53.044oai:locus.ufv.br:123456789/206Repositório InstitucionalPUBhttps://www.locus.ufv.br/oai/requestfabiojreis@ufv.bropendoar:21452016-04-06T11:00:53LOCUS Repositório Institucional da UFV - Universidade Federal de Viçosa (UFV)false
dc.title.por.fl_str_mv Efeito de componentes da matriz na análise de agrotóxicos por cromatografia gasosa
dc.title.alternative.eng.fl_str_mv Effect of components of the matrix in pesticide analysis by gas chromatography
title Efeito de componentes da matriz na análise de agrotóxicos por cromatografia gasosa
spellingShingle Efeito de componentes da matriz na análise de agrotóxicos por cromatografia gasosa
Pinho, Gevany Paulino de
Efeito de matriz
Agrotóxicos
Cromatografia gasosa
Matrix effect
Pesticides
Gas chromatography
CNPQ::CIENCIAS EXATAS E DA TERRA::QUIMICA::QUIMICA ANALITICA
title_short Efeito de componentes da matriz na análise de agrotóxicos por cromatografia gasosa
title_full Efeito de componentes da matriz na análise de agrotóxicos por cromatografia gasosa
title_fullStr Efeito de componentes da matriz na análise de agrotóxicos por cromatografia gasosa
title_full_unstemmed Efeito de componentes da matriz na análise de agrotóxicos por cromatografia gasosa
title_sort Efeito de componentes da matriz na análise de agrotóxicos por cromatografia gasosa
author Pinho, Gevany Paulino de
author_facet Pinho, Gevany Paulino de
author_role author
dc.contributor.authorLattes.por.fl_str_mv http://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4131534A6
dc.contributor.author.fl_str_mv Pinho, Gevany Paulino de
dc.contributor.advisor-co1.fl_str_mv Reis, César
dc.contributor.advisor-co1Lattes.fl_str_mv http://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4785327P6
dc.contributor.advisor-co2.fl_str_mv Queiroz, Maria Eliana Lopes Ribeiro de
dc.contributor.advisor-co2Lattes.fl_str_mv http://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4781671U3
dc.contributor.advisor1.fl_str_mv Neves, Antônio Augusto
dc.contributor.advisor1Lattes.fl_str_mv http://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4788868U1
dc.contributor.referee1.fl_str_mv Collins, Carol Hollingworth
dc.contributor.referee1Lattes.fl_str_mv http://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4787830U1
dc.contributor.referee2.fl_str_mv Coutrim, Maurício Xavier
dc.contributor.referee2Lattes.fl_str_mv http://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4785465J7
contributor_str_mv Reis, César
Queiroz, Maria Eliana Lopes Ribeiro de
Neves, Antônio Augusto
Collins, Carol Hollingworth
Coutrim, Maurício Xavier
dc.subject.por.fl_str_mv Efeito de matriz
Agrotóxicos
Cromatografia gasosa
topic Efeito de matriz
Agrotóxicos
Cromatografia gasosa
Matrix effect
Pesticides
Gas chromatography
CNPQ::CIENCIAS EXATAS E DA TERRA::QUIMICA::QUIMICA ANALITICA
dc.subject.eng.fl_str_mv Matrix effect
Pesticides
Gas chromatography
dc.subject.cnpq.fl_str_mv CNPQ::CIENCIAS EXATAS E DA TERRA::QUIMICA::QUIMICA ANALITICA
description This work aimed to systematically study the matrix effect on the measurement of pesticides chlorpyrifos, λ−cyhalothrin, cypermethrin and deltamethrin by gas chromatography with electron capture detector. The matrix effect is attributed to the presence of co-extractives in the organic phase during extraction. In this work, the phenomenon matrix effect is described in detail in a review discussing qualitative and quantitative aspects as well as techniques used to minimize it. Also reports results that quantify co-extractive interference with the chromatographic response of the four pesticides. There was a positive matrix effect after GC saturation with multiple injections of tomato organic extracts for the four pesticides. It was also found that the longer the retention time, the greater the matrix effect (10% for chlorpyrifos, 103% for λ-cyhalothrin, 162% for cypermethrin and 300% for deltamethrin), and that the internal standard minimizes the effect, but not eliminate it. An in-depth study of chlorpyrifos and deltamethrin adsorption on the injector and chromatography column was carried out. These were the pesticides that showed the lowest and greatest matrix effect, respectively, in previous studies. The capacity of chlorpyrifos and deltamethrin being adsorbed in the injector and chromatography column was assessed by plotting three isotherms with the injector at 310, 280 and 250°C and modifying the heating rate of the column to 10 and 30 °C min-1. For a range of concentrations between 5 and 500 µg L-1, the results showed that the higher the injector temperature (310 ° C) and the lower the heating rate of the chromatography column (10 °C min-1), the lower is the pesticide adsorption in the chromatography system. The results also showed that deltamethrin may present characteristics of protective analyte, reducing chlorpyrifos adsorption in the analysis of analyte standard solutions in pure solvent. A simple and practical method for identification and quantification of chlorpyrifos, λ-cyhalothrin, deltamethrin and cypermethrin in honey samples was also optimized and validated. The method is based on liquid-liquid extraction and purification at low temperature using the extractor mixture acetonitrile:ethyl acetate (6.5 mL: 1.5 mL). An additional clean-up step was performed with 2.0 g of florisil before analysis by gas chromatography. The efficiency of the technique was shown to be satisfactory (> 85%) and chromatographic response was linear for all pesticides in the range 0033 - 0.17 µg g-1, with correlation coefficients above 0.99. Limits of detection and quantification were below 0.017 and 0033 µg g-1 respectively. The proposed method was applied to 11 honey samples and detected residues of chlorpyrifos and λ-cyhalothrin in two samples, at concentrations below the MRLs established for food products. The presence of these compounds was confirmed by mass spectrometry in the SIM mode (GC-MS-SIM). Finally, the influence of chemical constituents of nine matrices (honey, tomatoes, milk, apples, soil, potatoes, liver, rump meat and water) on the quantification of the pesticides by GC-ECD was studied. With this purpose, organic extracts of each matrix were obtained from LLE-LTP or SLE-LTP and used to saturate the chromatography system. Standard pesticide solutions were injected before and after GC saturation with extracts of each matrix. Variation of chromatographic responses was evaluated by principal component analysis (PCA) and hierarchical cluster analysis (HCA). Results showed that the constituents of tomato organic extracts accounted for the greatest matrix effect on pyrethroid chromatographic responses in GC-ECD analyses (100 to 300%). This was confirmed by principal component analysis, which evaluated the distance of the response of tomato organic extracts from the other responses. Furthermore, the saturation of the chromatography system with extracts of water, soil, apple and honey decreased pyrethroid chromatographic responses.
publishDate 2009
dc.date.available.fl_str_mv 2009-08-13
2015-03-26T12:05:55Z
dc.date.issued.fl_str_mv 2009-04-24
dc.date.accessioned.fl_str_mv 2015-03-26T12:05:55Z
dc.type.status.fl_str_mv info:eu-repo/semantics/publishedVersion
dc.type.driver.fl_str_mv info:eu-repo/semantics/doctoralThesis
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dc.identifier.citation.fl_str_mv PINHO, Gevany Paulino de. Effect of components of the matrix in pesticide analysis by gas chromatography. 2009. 120 f. Tese (Doutorado em Agroquímica analítica; Agroquímica inorgânica e Físico-química; Agroquímica orgânica) - Universidade Federal de Viçosa, Viçosa, 2009.
dc.identifier.uri.fl_str_mv http://locus.ufv.br/handle/123456789/206
identifier_str_mv PINHO, Gevany Paulino de. Effect of components of the matrix in pesticide analysis by gas chromatography. 2009. 120 f. Tese (Doutorado em Agroquímica analítica; Agroquímica inorgânica e Físico-química; Agroquímica orgânica) - Universidade Federal de Viçosa, Viçosa, 2009.
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