Microextraction in Packed Sorbent for the Determination of Pesticides in Honey Samples by Gas Chromatography Coupled to Mass Spectrometry

Abstract

The present work describes the development and analytical validation of a method involving microextraction packed sorbent and gas chromatography coupled to mass spectrometry (MEPS-GC-MS) for the multi-residue analysis of 22 pesticides (permethrin, fenpropathrin, aldrin, α-hexachlorocyclohexane, β-hexachlorocyclohexane, lindane, vinclozolin, endosulfan, heptaclor, dodecaclor, tetradifon, 1,1-dichloro-2,2-bis (p-chlorophenyl)ethane, 1,1-bis(p-chlorophenyl)-2,2-dichloroethylen, carbofuran, carbaryl, pirimiphos methyl, chlorpyriphos, dimethoate, disulfoton, fenamiphos, terbufos and profenofos) in honey samples. The MEPS variables of sample pH, draw-eject cycles, ionic strength and desorption procedure were optimized to improve the sensitivity of the proposed method. The method was shown to be linear at concentrations ranging from 2, 5 and 10 ng/g (limit of quantification) to 75-100 ng/g. These values are lower than those established as the maximum residue limits for honey samples. The accuracy values (82-114%) were adequate for all the analytes, as were the inter-day precision data, with coefficient of variation lower than 14%. On the basis of analytical validation, the MEPS-GC methodology has been shown to be a promising alternative for the analysis of pesticides in honey samples. The MEPS packed syringe can be reused 40 times for honey samples, whereas the conventional solid-phase extraction (SPE) column can only be used once. Compared with liquid-liquid extraction and SPE, MEPS is able to reduce sample preparation time and organic solvent consumption.

Determination of Pesticide Residues in Food of Animal Origin

“…Miniaturized techniques have also been applied for the extraction of pesticide residues from honey samples by dispersive liquid-liquid microextraction (DLLME) [18][19][20] , microextraction in packed sorbent (MEPS) 21 and solid-phase microextraction (SPME) 22 . Moreover, Campillo et al (2013) have combined SPE extraction with DLLME for the extraction of neonicotinoids from honey 23 .…”

“…DLLME is a simple and rapid extraction technique that consumes low volume of organic solvent. On the other hand, MEPS can be considered a green extraction method because the sorbent can be reused for more than 40 times with minimum loss of extraction efficiency 21 .…”

“…There are three modes of GC-MS available, electron impact (EI), positive chemical ionization (PCI) and negative chemical ionization (NCI), with the first one being the most widely used. Due to its adequate sensitivity and selectivity, GC-MS in selected ion monitoring (SIM) is commonly used in the determination of different classes of pesticides in animal tissues 8,16,62 , milk 8,57 , fish 8,16 and honey [20][21][22]24,49,60,75 . GC-MS/MS commonly provides higher sensitivity and selectivity, as well as higher degree of certainty than GC-MS in SIM mode, because it involves at least two stages of mass analysis, separated by a fragmentation step.…”

Determination of pesticides in sugarcane juice employing microextraction by packed sorbent followed by gas chromatography and mass spectrometry

“…. Nevertheless, few studies on MEPS as a sample preparation and concentration step for the analyses of pesticide residues in food and environmental samples have been conducted .…”