Multiresidue Analysis of Pesticides and Metabolites from Fruits and Vegetables by Gas Chromatography—Time-of-Flight Mass Spectrometry

Abstract

Summary. This work describes the comparison of five sample extraction methods for the determination of pesticide residues in grapes and vegetables by using gas chromatography-time-of-flight mass spectrometry (GC-TOF-MS). These methods were based on original methods QuEChERS, mini-Luke, ethyl acetate, and DIN EN 15637, and some of these were slightly modified to increase the number of identified and quantified pesticides, to improve their quantification limits, and to be fast and less expensive in terms of material cost. The acceptable performance parameters combined with the properties of easy and quick handling and cost-effectiveness have made mini-Luke modified extraction method as the most favorable in the pesticide residues analysis from grapes and tomatoes by GC-TOF-MS. The efficiency of the chosen extraction method was also verified for lettuce; for this matrix, a cleanup step with graphitized black carbon (GBC) was added. Analysis of extracts was carried out by GC-TOF-MS within 29.2 min run time. The GC method was validated for grapes and tomatoes in terms of linearity, accuracy, limit of detection (LOD), and limit of quantification (LOQ). Good linearity with correlation coefficients (r 2 ) higher than 0.98 was obtained. For most analytes from both matrices, recoveries were in the range of 71-120% and LOQ values in the range of 0.01-0.05 mg kg −1 . The GC-TOF-MS and modified mini-Luke extraction methods were successfully tested on real vegetable and fruit samples belonging to the same commodities group as those from validated methods according to European Guide DG SANCO 12571/2013 (tomatoes, pepper, cucumber, potatoes, carrots, eggplants, onion, lettuce and grapes) and in proficiency EU tests.

Analysis of multiresidue pesticides in dried hops by LC-MS/MS using QuEChERS extraction together with dSPE clean-up

“…The new techniques included a method using methanol extraction and clean-up using solid-phase extraction (SPE) columns with diatomaceous earth (7) or modification of the ethyl acetate-based multiresidue method (Mol et al (8)), where the GPC cleaning step was replaced by dispersive SPE using the mixture of primary-secondary amine (PSA) and graphitized carbon black (GCB). Methods based on this approach using SPE as a cleaning step or without any clean-up were published for a wide range of matrices involving fruits or vegetables (9)(10)(11). In comparison with these matrices, the analysis of pesticide residues in hops is challenging owing to the presence of soft and hard resins plus other phenolic compounds, chlorophyll pigments and hop essential oils.…”

Application of gas and liquid chromatography coupled to time‐of‐flight mass spectrometry in pesticides: Multiresidue analysis

“…Recently a GC‐TOF‐MS method for the analysis of 135 pesticides in vegetables was developed and validated (Meghesan‐Breja, Cimpoiu, & Hosu, ). Five extraction methods were investigated, namely QuEChERS, mini‐Luke, EtOAc and DIN EN 15637.…”

Identification and quantification of some pesticide metabolites from vegetables by GC-TOF-MS and LC-MS-QQQ

“…The GC-TOF-MS assay is performed using the previously developed and validated method for 85 pesticides analysis from various fruits and vegetables, including the parent pesticides of the target metabolites [22]. Each compound is identified and quantified using the retention times, by monitoring three selected m/z ions ( Table 2) and by comparing registered mass spectra with those from ten spectra libraries (overlap of at least 70%).…”