A simple and efficient multi-residue method based on QuEChERS for pesticides determination in palm oil by liquid chromatography time-of-flight mass spectrometry

Abstract

In this study, a rapid, specific and sensitive multi-residue method based on acetonitrile extraction followed by dispersive solid-phase extraction (d-SPE) clean-up was implemented and validated for multi-class pesticide residues determination in palm oil for the first time. Liquid-liquid extraction followed by low-temperature precipitation procedure was evaluated in order to study the freezing-out clean-up efficiency to obtain high recovery yield and low co-extract fat residue in the final extract. For clean-up step, d-SPE was carried out using a combination of anhydrous magnesium sulphate (MgSO(4)), primary secondary amine, octadecyl (C(18)) and graphitized carbon black. Recovery study was performed at two concentration levels (10 and 100 ng g(-1)), yielding recovery rates between 74.52% and 97.1% with relative standard deviation values below 10% (n = 6) except diuron. Detection and quantification limits were lower than 5 and 9 ng g(-1), respectively. In addition, soft matrix effects (≤±20%) were observed for most of the studied pesticides except malathion that indicated medium (20-50%) matrix effects. The proposed method was successfully applied to the analysis of suspected palm oil samples.

Simultaneous analysis of herbicides pendimethalin, oxyfluorfen, imazethapyr and quizalofop-p-ethyl by LC–MS/MS and safety evaluation of their harvest time residues in peanut (Arachis hypogaea L.)

“…In the actual QuEChERS method by Anastassiades et al 2003 and QuEChERS method used by other authors for pesticides determination in fatty matrix (Cunha et al 2007;Sobhanzadeh et al 2012) the procedure used 1 g sample mL −1 extract. But in this method, it was 0.25 g sample mL −1 extract.…”

“…In recent years, QuEChERS (quick, easy, cheap, rugged, effective and safe) sample preparation approach (Anastassiades et al 2003), has been emerged as the most universal sample preparation method and this extraction technique is gaining popularity due to simplicity, use of minimal volumes of non-chlorinated organic solvents which, in the era of green chemistry (Pinto et al 2011;Ferreira et al 2014;Sadowska-Rociek et al 2014). It has applicability to a wide range of organic contaminants including pesticides (Wilkowska and Biziuk, 2011) of differing polarities, volatilities and matrices; this extraction technique has been successfully used for the extraction of pesticides from fatty matrices, such as olives (Cunha et al 2007), palm oil (Sobhanzadeh et al 2012), milk, egg, and avocado (Lehotay et al 2005) and rapeseed (Jiang et al 2012). Many modifications and studies on QuEChERS method have been published and one of its important modifications includes use of additional water to obtain necessary moisture for better recovery in case of dry samples (Koesukwiwat et al 2008;Mastovska et al 2010).…”

Técnicas de análise de resíduos de agrotóxicos em alimentos de origem vegetal: uma revisão

“…Segurança Alimentar e Nutricional, Campinas, 22(2):766-777, 2015 carotenóides e clorofila [33][34][35] . Nestes casos podem ser utilizados na etapa de limpeza o carbono grafitizado (eficiente na remoção de pigmentos) e o C18 (remove interferentes não polares).…”

Evaluation of QuEChERS Sample Preparation and Gas Chromatography Coupled to Mass Spectrometry for the Determination of Pesticide Residues in Grapes

“…Some modifications were proposed to the QuEChERS method, e.g., buffering, 5,6 use of others extraction solvents, 7 different sorbents as graphitized carbon black (GCB), 8 octadecyl (C18), Florisil ® (magnesium silicate) and alumina, 9 and the use of low temperature precipitation for fatty matrices. 10 These modifications allowed the extraction of a large number of pesticides from different classes and matrices. Most part of the modifications was focused in the clean-up step and different sorbents have been used besides primary and secondary amine (PSA) and C18.…”