Wide-scope screening of pesticides in fruits and vegetables using information-dependent acquisition employing UHPLC-QTOF-MS and automated MS/MS library searching

Abstract

This paper presents an application of ultra-high performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UHPLC-QTOF-MS) for simultaneous screening and identification of 427 pesticides in fresh fruit and vegetable samples. Both full MS scan mode for quantification, and an artificial-intelligence-based product ion scan mode information-dependent acquisition (IDA) providing automatic MS to MS/MS switching of product ion spectra for identification, were conducted by one injection. A home-in collision-induced-dissociation all product ions accurate mass spectra library containing more than 1700 spectra was developed prior to actual application. Both qualitative and quantitative validations of the method were carried out. The result showed that 97.4 % of the pesticides had the screening detection limit (SDL) less than 50 μg kg and more than 86.7 % could be confirmed by accurate MS/MS spectra embodied in the home-made library. Meanwhile, calibration curves covering two orders of magnitude were performed, and they were linear over the concentration range studied for the selected matrices (from 5 to 500 μg kg for most of the pesticides). Recoveries between 80 and 110 % in four matrices (apple, orange, tomato, and spinach) at two spiked levels, 10 and 100 μg kg, was 88.7 or 86.8 %. Furthermore, the overall relative standard deviation (RSD, n = 12) for 94.3 % of the pesticides in 10 μg kg and 98.1 % of the pesticides in 100 μg kg spiked levels was less than 20 %. In order to validate the suitability for routine analysis, the method was applied to 448 fruit and vegetable samples purchased in different local markets. The results show 83.3 % of the analyzed samples have positive findings (higher than the limits of identification and quantification), and 412 commodity-pesticide combinations are identified in our scope. The approach proved to be a cost-effective, time-saving and powerful strategy for routine large-scope screening of pesticides.

Identification of small molecules using accurate mass MS/MS search

“…Fields of applications for MS/MS matching include nearly all scientific areas that make use of LC‐MS/MS, GC‐MS/MS, and tandem mass spectrometry data . This includes metabolic profiling, dereplication of complex natural extracts, fungal metabolites, marine products, plant based metabolic profiling and plant metabolomics, lipid analysis, toxicology analysis, environmental analysis, food contaminants, forensics, drugs, and pesticide screening, as well as statistical MS/MS fragmentation analysis and network maps for visualizations . For those cases where no reference spectrum is found in any database, purely computational approaches have to be taken.…”

Salt‐assisted acetonitrile extraction and HPLC‐QTOF‐MS/MS detection for residues of multiple classes of pesticides in human serum samples

“…The confirmatory MS 1 data of the 34 pesticides and MS 2 data of TCP and DEP (≤3 ppm) were referenced and modified using the Personal Compound Database and Library Manager (version B 07.00, Agilent Technologies) [37]. The recovery data and descriptive statistics from the HPLC-QTOF-MS procedures were calculated using Microsoft Excel (version 2007; Redmond, WA, USA).…”

“…In this study, three protein removal reagents as purification reagents and four volume ratios of serum-topurification reagent were tested for optimizing the extraction method and improving the detection of residues of multi-classes pesticides. Also 34 pesticides were selected from nine representative groups of chemicals, namely carbamate, imidazolinone, neonicotinoid, organophosphate, triazine, triazole, urea, strobilurin, and aryloxyalkanoic (Supporting Information Table S1), which were frequently present in food [3,[32][33][34][35][36][37], and compared the recoveries and detection limits of these pesticides in human serum. This efficient residue analysis method could be used to improve limits of detection for multi-classes pesticides in human serum.…”

Analytical methods for the routinely evaluation of pesticide residues in lemon fruits and by products

“…The omnipresence of pesticide residues in citrus products was pointed out as over a total of 8920 analyzed citrus fruits in South Africa, 84% contained traces of imidazole-benzimidazole fungicides and 14% of organophosphorus insecticides [5]. In China, imazalil and thiabendazole residues were determined in 19 orange and 21 mandarin samples using UHPLC-QTOF-MS and automated MS/MS library searching [6]. Imazalil was found in all the samples from different countries of a common, internationally sold carbonated orange juice except the sample of US where no natural juice is used in this production [7] Furthermore, the European Pharmacopoeia considers that pesticide residues analysis should be carried out in cold pressed essential oils,such as the citric ones, due to the potential harm they pose when included in pharmaceutical formulations [8].…”