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

Abstract

As a result of the low water content and high fat matrices in nuts, it is very difficult to simultaneously determine multi-pesticides in trace levels. Here, a sample pretreatment method was developed in which, microwave-assisted solvent extraction was firstly used to extract pesticides, and then a two-step cleanup method was conducted combining freeze-out with dispersive solid-phase extraction to remove the lipidic matrix. By this way, 106 pesticides were simultaneously determined in the complicated nut sample by using an ultra-high pressure liquid chromatography coupled with a tandem mass spectrometer. Average recoveries were 75.3-119.3% with relative standard deviations < 14% at three concentration levels. The limits of detection and quantification were in the ranges of 0.3-3.0 and 1.0-10.0 μg/kg, respectively. Furthermore, the method was successfully applied to the determination of pesticides in 180 commercial nut samples.

Development and evaluation of microwave‐assisted and ultrasound‐assisted methods based on a quick, easy, cheap, effective, rugged, and safe sample preparation approach for the determination of bisphenol analogues in serum and sediments

“…The recovery obtained by the basic QuEChERS method was lower than those obtained by MA‐ and UA‐QuEChERS for both serum and sediments, suggesting that the performance of the method was improved by introducing microwave and ultrasound. Based on the experimental results, we noticed that although the working mechanisms of microwave and ultrasound were different, they both produced elevated temperature and pressure during the extraction cycles, which improved the extraction efficiency . However, some different modifications for use with serum and sediment samples deserve attention.…”

“…MAE and UAE are widely used sample preparation techniques for environmental samples (e.g., sludge and sediments) and biosamples (urine and serum) . MAE employs microwave energy to heat both the solvent and the sample . UAE utilizes ultrasound energy to produce cavitation, which enhances heat and mass transfer .…”

A Combination of Chromatography with Tandem Mass Spectrometry Systems (UPLC-MS/MS and GC-MS/MS), Modified QuEChERS Extraction and Mixed-Mode SPE Clean-Up Method for the Analysis of 656 Pesticide Residues in Rice

“…The selection of the extraction solvent can remarkably improve the purification of the analyte from the sample matrix [8]. Among the most prevalent solvents, MeCN has been commonly utilized in the QuEChERS extraction protocol since it can limit the influences of non-polar compounds such as fats, waxes, and pigments present in the sample matrix compared to other solvents [11]. Moreover, previous studies pointed out that the use of acetic acid considerably improves the extraction efficiency of the target analytes even at trace levels [12].…”

Microwave-Based Technique for Fast and Reliable Extraction of Organic Contaminants from Food, with a Special Focus on Hydrocarbon Contaminants

“…Among these, it is worthy of mention the combination of MAE with dispersive solid phase micro-extraction (D-µ-SPE), till now not applied to hydrocarbon contaminants but successfully applied to the extraction of pesticides [16,17], antibiotic residues [18] and mycotoxins [19] from a wide range of food. The combination of MAE (more precisely MAS, because a basic hydrolysis is performed) with dispersive liquid-liquid micro-extraction (DLLME) is for sure the most utilized method, for extraction/purification of food contaminants, particularly of hydrocarbon contaminants (as detailed in the next paragraphs).…”