Analysis of tomato matrix effect in pesticide residue quantification through QuEChERS and single quadrupole GC/MS

Abstract

The detection of pesticide in tomato (Solanum lycopersicum L.) matrix using Gas Chromatography hyphenated to Mass Spectrometry detector (GC/MS) can affect the sensitivity of the analysis by enhancement or suppression of their chromatography response, the percentages of recoveries and leading to errors in the quantification of the pesticides. In this study, the matrix effect was investigated using nine pesticides, and "Quick, Easy, Cheap, Effective, Rugged and Safe" (QuEChERS)-GC/MS analytical technique was validated for pesticides multiresidue analysis. The matrix effect was determined using not statistical and statistical procedures including ANOVA, with similar results. Strong negative matrix effect was found for the pesticides trifluralin, 4,4'-DDT, and permethrin, resulting in the increment of the chromatogram background and a decrease in their detection responses. Contrary, an enhancement induced by the matrix presence was obtained for carbaryl and azinphos methyl, showing a positive medium matrix effect. While, dimethoate, simazine, 4,4'-DDE, and iprodione did not exhibit matrix effect. The detection limits (LOD) obtained, varied from 0.003 to 0.1 mg kg -1 . Reproducibility was less than 20% for each pesticide. Recoveries were found to be between 71% and 121%, except for dimethoate, carbaryl, and azinphos methyl which reached values lower than 70%. Recoveries relative standard deviations were less than 22%. Quechers-GC/MS technique was used for evaluation of fresh commercial tomatoes samples, detecting carbaryl in all of them, but in concentration levels lower than the maximum residue limits according to regulations of Codex.

Investigation of the effects of household processing on the reduction rate of chlorpyrifos, metalaxyl and diazinon residues in orange fruit

“…Linearity in solvent and orange matrix extract for metalaxyl, diazinon and chlorpyrifos (Table 4) was acceptable, as indicated by the values of regression coefficient (r 2 ) that were > 0.99 for all compounds in solvent, and in the matrix (De Sousa et al, 2012;Domínguez et al, 2014). According to the European Commission guideline SANTE/11813/2017, the acceptable RSD should be ≤20%, where the fi t of calibration inspected by calculation of the residuals avoids over-reliance on the correlation coeffi cient.…”

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“…The criterion of acceptation was that the percentage of recovering is between 70 and 120 % (EURACHEM, 1998 (Domínguez et al, 2014) y diclorvos (LOD=9.72 y LOQ=32.4 mg/kg) (Jahanmard et al, 2015).…”

“…reported LODs and LOQs higher for dimethoate (LOD = 0.1 and LOQ = 0.4 mg/kg) (Domínguez et al, 2014) and dichlorvos (LOD = 9.72 and LOQ = 32.4 mg/kg) (Jahanmard et al, 2015).…”

VALIDACIÓN DE UN MÉTODO PARA EL ANÁLISIS DE RESIDUALIDAD DE PLAGUICIDAS EN GULUPA (Passiflora edulis f. edulis)

“…El porcentaje calculado representa la cantidad de compuestos que hacen parte de la matriz que participan como interferencias, y no fueron retirados de forma efectiva en los procesos de limpieza a los que es sometida la muestra y no permiten una mejor detección y cuantificación de los compuestos de interés analítico (Lehotay et al, 2010); este hecho es más significativo en el plaguicida malation con un porcentaje de efecto matriz de 486.8 %, lo cual indica un efecto matricial prominente mientras que metil-paration, deltametrina y clorotalonilo, cuentan con 101.3 %, 30.1 %, 42.3 %, respectivamente, que representa que no hay efecto matricial sobre metil-paration, entre tanto para deltametrina y clorotalonilo existe un efecto represivo (Domínguez et al, 2014;Ahumada et al, 2012). Existen compuestos que inducen el efecto matriz tales son los casos de acefato, malation, dimetoato y pirazofos, conocidos por su gran sensibilidad a procesos de adsorción en el vaporizador del inyector (Hajlová & et al, 1998).…”

“…El método QuEChERS, acrónimo en inglés de Quick, Easy, Cheap, Efective, Robust and Safe, desarrollado por Anastassiades y colaboradores en 2003, se caracteriza por la disminución de solventes y reactivos usados en el procedimiento y la facilidad del tratamiento de las muestras, particularidades que recientemente, han llevado a este método a extenderse para determinar otros contaminantes incluidos cresoles, benceno, tolueno, etilbenceno y xilenos, hidrocarburos aromáticos policíclicos (HAP) y bifenilos policlorados (PCB) (Domínguez et al, 2014;Norli et al, 2011;Tuzimski & Rejczak, 2014), en los que se exploran otras matrices diferentes a los productos frescos alimenticios tales como agua, suelo y muestras biológicas (Norli et al, 2011).Éste se constituye de una extracción, limpieza y análisis instrumental empleando cromatografía gaseosa acoplada a detector de microcaptura de electrones (GC-µECD) para este caso (Oliveira et al, 2014). Sin embargo, el análisis instrumental se puede realizar por cromatografía de gases acoplada a un detector de masas o por cromatografía líquida de alta eficacia (HPLC) (Godula et al, 1999).…”