Applications of LC/ESI-MS/MS and UHPLC QqTOF MS for the determination of 148 pesticides in fruits and vegetables

Abstract

This paper presented the applications of liquid chromatography electrospray ionization tandem mass spectrometry (LC/ESI-MS/MS) and ultra-high-pressure liquid chromatography electrospray ionization quadrupole time-of-flight mass spectrometry (UHPLC QqTOF MS) for the determination of 148 pesticides in fruits and vegetables. Pesticides were extracted from fruits and vegetables using a buffered QuEChERS method. Quantification was achieved using matrix-matched standard calibration curves with isotopically labeled standards or a chemical analog as internal standards in an analytical range from 5 to 500 microg/kg. The method performance parameters including overall recovery, intermediate precision, and measurement uncertainty were evaluated according to a statistically designed experiment, i.e., a nested design. For LC/ESI-MS/MS, 95% of the pesticides had recoveries between 81% and 110%; 97% had an intermediate precision < or = 20%; and 95% (in fruits) or 93% (in vegetables) showed measurement uncertainty < or = 40%. Compared to LC/ESI-MS/MS, UHPLC QqTOF MS showed a relatively poor repeatability and large measurement uncertainty. About 93% (in fruits) or 94% (in vegetables) of the pesticides had recoveries between 81% and 110%; 86% (in fruits) or 90% (in vegetables) had an intermediate precision < or = 20%; and 79% (in fruits) or 88% (in vegetables) showed measurement uncertainty < or = 40%. LC/ESI-MS/MS proved to be the first choice for quantification or pre-target analysis due to its superior sensitivity and good repeatability. UHPLC QqTOF MS provided accurate mass measurement and isotopic patterns, and was an ideal tool for post-target screening and confirmation.

The challenges of developing a generic extraction procedure to analyze multi‐class veterinary drug residues in milk and honey using ultra‐high pressure liquid chromatography quadrupole time‐of‐flight mass spectrometry

“…Sample extraction procedures followed the buffered QuEChERS or AOAC Official Method 2007.01 [14,15] without dispersive solid-phase extraction clean-up step. A 10 g honey or milk sample was weighed into a 50-ml centrifuge tube (VWR International, Mississauga, Ontario, Canada).…”

“…The buffered QuEChERS method or AOAC Official Method 2007.01 [14,15] that included both extraction and/or clean-up was explored for its applicability for extraction of veterinary drug residues from honey and milk samples. The extraction step entailed the addition of 10 ml of a mixture of acetonitrile and acetic acid (99 + 1, v/v) to a sample (10 g), which required a 45 s shake before 1 g sodium acetate and 4.0 g MgSO 4 were added.…”

Assessment of pesticide residue levels among locally produced fruits and vegetables in Monze district, Zambia

“…Pesticides are used to preserve their quality and prevent diseases. While the use of these chemical pesticides enhances the farmer's productivity, inappropriate pesticide use poses health hazards to consumers, other organisms and the environment (Wang et al 2010).…”

Liquid Chromatographic Determination of Etofenprox Residues in Foods with Mass-Spectrometric Confirmation

“…Recently, several multi-residue methods for the purpose of screening of diverse pesticide residues including etofenprox had been reported using GLC/mass spectrometry (MS) (Paya et al, 2007;Cervera et al, 2010) or liquid chromatography (LC)/MS (Sannino et al, 2004;Paya et al, 2007;Lacina et al, 2010;Wang et al, 2010).…”