Analysis of Pesticides in Nuts by Online Reversed-Phase Liquid Chromatography−Gas Chromatography Using the Through-Oven Transfer Adsorption/Desorption Interface

Abstract

A new method to determine pesticide residues in nuts is presented, in which the pesticides are extracted from samples with a small amount of ethyl acetate and anhydrous sodium sulfate. No additional cleanup or concentration steps are necessary. The extract is directly injected into the high-pressure liquid chromatograph, where preseparation of the pesticide residues from other components coextracted from the nuts is carried out using methanol/water as the eluent. The selected liquid chromatography fraction containing the pesticides is automatically transferred to the gas chromatograph using the through-oven transfer adsorption/desorption interface. The calculated limits of detection for each pesticide varied from 0.1 to 61.3 microg/kg. The repeatabilities of the analysis and the overall procedure (extraction and analysis) were satisfactory. No variations in the retention time were observed. The method was applied to the analysis of pistachio nut, peanut, walnut, hazelnut, and sunflower seed.

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.)

“…Concerning the analysis of pesticide residues in peanut, there are only few works in the published (Li et al 2007a;Cortes et al 2008;Wang et al 2009). In most cases, studies have been carried out only for insecticides or more particular group of insecticides like organophosphorous (OPs) (Li et al 2007b, Su et al 2011, whereas methods are mostly available to determine pesticide residues in peanut oil and only few studies reported in raw peanut.…”

Simultaneous determination of 106 pesticides in nuts by LC–MS/MS using freeze‐out combined with dispersive solid‐phase extraction purification

“…However, in the cultivation of nut, pesticides are widely used either solely or in various combinations. And some of them are hydrophobic and can be absorbed in the lipidic matrix of the nuts (fat content 50–70%) . These residues would cause hazardous effects to both humans and environment, and has become of increased concern world wide.…”

“…Cortes et al. utilized a LC–GC platform to determine pesticides in nuts after extraction with a small amount of AcOEt and anhydrous sodium sulfate . Haroldo et al.…”

“…And some of them are hydrophobic and can Abbreviations: AcOEt, ethyl acetate; CE, collision energy; DP, declustering potential; d-SPE, dispersive solid phase extraction; GPC, gel permeation chromatography; MSPD, matrix solid-phase dispersion; MeOH, methanol; MeCN, acetonitrile; MRM, multiple reaction monitoring; ME, matrix effects; TIC, total ion chromatogram Conflict of interest: The authors have declared no conflict of interest. be absorbed in the lipidic matrix of the nuts (fat content 50-70%) [2]. These residues would cause hazardous effects to both humans and environment, and has become of increased concern world wide.…”

Development of an analytical method for the determination of the misuse in sports of boldenone through the analysis of urine by on-line coupling liquid chromatography–gas chromatography–combustion–isotope ratio mass spectrometry

“…The TOTAD interface has been used for the on-line LC-GC analysis of many different analytes in complex matrices such as food [14,15] or environmental samples [16,17]. Toledano et al [13] designed an automatic fraction collector which permits the different fraction eluted in LC to be stored automatically and sent individually to the GC by means of the TOTAD interface.…”