Explanation of the matrix-induced chromatographic response enhancement of organophosphorus pesticides during open tubular column gas chromatography with splitless or hot on-column injection and flame photometric detection

Erney, D. Ronald; Gillespie, Allesia M.; Gilvydis, Dalia M; Poole, Colin F.

doi:10.1016/0021-9673(93)85007-t

Cited by 312 publications

(159 citation statements)

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“…Embora os primeiros trabalhos sobre a influência da matriz nas análises de agrotóxicos por cromatografia tenham sido publicados a partir de 1981, [17][18][19][20][21][22][23] considera-se que o efeito de matriz foi sistematicamente estudado pela primeira vez por Erney et al 24 Além disso, esses autores verificaram que melhor precisão dos resultados era obtida após injeções sucessivas da solução-padrão preparada no extrato da matriz isenta dos agrotóxicos, ou seja, só se conseguia boa repetitividade dos resultados após a saturação do sistema cromatográfico com os componentes da matriz. 24 Em avaliação inicial do mecanismo do efeito de matriz, Erney et alverificaram que fatores como tipo de matriz, concentração do agrotóxico na amostra, tipo de injetor e temperatura do sistema cromatográfico poderiam influenciar também nos resultados.…”

Section: Aspectos Históricosunclassified

“…24 Em avaliação inicial do mecanismo do efeito de matriz, Erney et alverificaram que fatores como tipo de matriz, concentração do agrotóxico na amostra, tipo de injetor e temperatura do sistema cromatográfico poderiam influenciar também nos resultados. 24 A partir desse estudo, realizaram-se novas pesquisas para identificar os fatores que influenciavam no efeito de matriz e as possíveis medidas a serem realizadas para minimizar os problemas.…”

Section: Aspectos Históricosunclassified

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Efeito de matriz na quantificação de agrotóxicos por cromatografia gasosa

Pinho¹,

Neves²,

Queiroz³

et al. 2009

Quím. Nova

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Recebido em 8/2/08; aceito em 2/9/08; publicado na web em 15/4/09 MATRIX EFFECT IN PESTICIDE QUANTIFICATION BY GAS CHROMATOGRAPHY. The lack of accuracy of a chromatographic method can be associated with the matrix effect. This effect is observed in pesticide quantification by gas chromatography when the chromatographic signals of standards prepared in solvents are compared with those of the analyte in extracts of complex matrices. In the competition between the matrix components and the pesticides for the active sites of the liner, a larger amount of pesticides is transferred to the column, giving apparent extractions above 100%. In this work, we discuss factors that contribute to the matrix effect and present some attempts to overcome the problem.

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Section: Aspectos Históricosunclassified

Efeito de matriz na quantificação de agrotóxicos por cromatografia gasosa

Pinho¹,

Neves²,

Queiroz³

et al. 2009

Quím. Nova

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“…MEs are notoriously variable in occurrence and intensity, the GC technique being particularly prone to them [5,28]. The ME is a phenomenon that makes the analyte chromatographic response to be different (higher or lower) in the matrix presence.…”

Section: Introductionmentioning

confidence: 99%

“…It is assumed that the matrix components block the active sites in the GC system, mainly in the injection liner, protecting the analytes from adsorption or alteration during transfer from the Silvia de Sousa Freitas Fernando M. Lanc -as injector to the column, improving the injection efficiency [28,29]. Moreover, interfering matrix components can affect the reproducibility and accuracy of the developed procedure, leading to erroneous results in quantitation [30][31][32].…”

Section: Introductionmentioning

confidence: 99%

“…The MSPD procedure allows the extraction and cleanup of analytes in a single step and is based on the dispersion of the sample on an adsorbent, such as florisil, C18, alumina or silica, followed by eluting with a small amount of solvent [24]. However, in spite of the fact that most of these modern methods provide a simple and rapid procedure for the determination of pesticides in fruits matrices, they do not avoid the presence of co-extracted matrix components that can result in a matrix effect (ME) in the pesticide analysis [25][26][27].MEs are notoriously variable in occurrence and intensity, the GC technique being particularly prone to them [5,28]. The ME is a phenomenon that makes the analyte chromatographic response to be different (higher or lower) in the matrix presence.…”

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Matrix effects observed during pesticides residue analysis in fruits by GC

Freitas¹,

Lanças²

2009

J of Separation Science

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The influence of the sample matrix in the GC-electron-capture detection analysis of the pesticides dimethoate, diazinon, chlorothalonil, parathion methyl and fenitrothion in fruits samples has been studied. Experiments have been carried out where the pesticide responses in standard solutions prepared in selected solvent were compared with their response when present in apple, mango, papaya, banana, pineapple and melon extracts. The presence of matrix effects (MEs) and their extent were shown to be simultaneously influenced by several factors (matrix concentration, matrix type, pesticide concentration, analytical range). Pronounced MEs were observed particularly for dimethoate and diazinon in all matrices tested; in lower concentrations, all pesticides presented significant ME. The other pesticides presented variable ME. Higher ME enhancement was detected at lower pesticide concentration levels of and/or at higher matrix concentration solutions. The ME detected for fenitrothion, in the analytical range evaluated, were dependent on matrix type. For each pesticide, solvent and matrix-matched calibrations were compared for all fruit samples, and it could be concluded that quantitation based on standard solutions prepared in blank matrix extract (matrix-matched calibration) should be used to compensate the MEs and to obtain more accurate results for the pesticides studied. IntroductionMost of the pesticide determination in food samples is usually performed using GC in combination with electroncapture detection (ECD) [1,2], nitrogen-phosphorus detection [2,3] or MS detection [4][5][6].Analytical procedures for determination of pesticides in fruit matrices are usually based on an extraction step, using conventional liquid-liquid extraction, followed by a clean-up procedure prior to chromatographic analysis [7,8]. Several methods based on supercritical fluid extraction [9, 10], solidphase extraction [11,12], solid-phase microextraction [13], stir bar sorptive extraction [14][15][16] and matrix solid-phase dispersion (MSPD) [1,5,[17][18][19][20][21][22][23] have been developed to overcome the drawbacks caused by using high amounts of glassware and toxic solvents in the classical liquid extraction methods.MSPD has proven useful as an extraction technique for the determination of pesticide residues in fruits and vegetables by GC [1,4] or LC [18,19]. The MSPD procedure allows the extraction and cleanup of analytes in a single step and is based on the dispersion of the sample on an adsorbent, such as florisil, C18, alumina or silica, followed by eluting with a small amount of solvent [24]. However, in spite of the fact that most of these modern methods provide a simple and rapid procedure for the determination of pesticides in fruits matrices, they do not avoid the presence of co-extracted matrix components that can result in a matrix effect (ME) in the pesticide analysis [25][26][27].MEs are notoriously variable in occurrence and intensity, the GC technique being particularly prone to them [5,28]. The ME is a phenomenon th...

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