title: Evaluation of MS2workflows in LC-Q-Orbitrap for pesticide multi-residue methods in fruits and vegetables.
abstract: LC-Q-Orbitrap efficiency was evaluated for pesticide multi-residue analysis by using three workflows involving simultaneous MS and MS2analysis. They were as follows: data-dependent MS2(dd-MS2), all-ion fragmentation (AIF) and variable data-independent analysis (vDIA). These MS2workflows were tested for the main method validation parameters such as detection and identification capabilities, repeatability, linear range and quantitation. QuEChER acetonitrile extracts (blanks and spiked with 166 pesticides) of 11 different fruits and vegetables were used for this evaluation. Blank extracts were analysed to evaluate isobaric compounds and potential false identification. Spiked extracts (at 0.01 and 0.1 mg kg-1) were analysed to evaluate the false negatives potentially produced (considering a retention mass window of 0.2 min). At 0.01 mg kg-1, dd-MS2had the highest identification rate (96-100%, depending on the matrix). In vDIA, it was 86-100% and in AIF 81-100%. But these two last workflows offered more possibilities for applying screening analysis. It was observed that application of the ion ratio criterion established in the SANTE Guidelines for identification can generate some artificial false negative results. It could be overcome by considering a mass error threshold (i.e. 5 ppm) as a selected criterion. Detection and quantitation were carried out in full-scan MS. MS2data were used for identification. Dd-MS2provided the highest number of points per chromatographic peak, and by that peak area, repeatability was the best (typically <10%). AIF and vDIA were characterised by longer cycle times; thus, the obtained peak area repeatability was slightly worse, but acceptable (<20%). All workflows showed very good linearity in the range 0.01-0.5 mg kg-1. The three MS2workflows were applied to real samples with good results. Graphical abstract LC-Q-Orbitrap was used for pesticide residues analysis in fruit and vegetables. Three approaches to MS2identificaton were evaluated.
authors.affiliation: European Union Reference Laboratory for Pesticide Residues in Fruit & Vegetables, University of Almeria, Agrifood Campus of International Excellence (ceiA3), Ctra. Sacramento s/n, La Cañada de San Urbano, Almeria, 04120, Spain.
authors.forename: Łukasz
authors.initials: Ł
authors.lastname: Rajski
authors.affiliation: European Union Reference Laboratory for Pesticide Residues in Fruit & Vegetables, University of Almeria, Agrifood Campus of International Excellence (ceiA3), Ctra. Sacramento s/n, La Cañada de San Urbano, Almeria, 04120, Spain.
authors.forename: María
authors.initials: M
authors.lastname: Del Mar Gómez Ramos
authors.affiliation: European Union Reference Laboratory for Pesticide Residues in Fruit & Vegetables, University of Almeria, Agrifood Campus of International Excellence (ceiA3), Ctra. Sacramento s/n, La Cañada de San Urbano, Almeria, 04120, Spain. amadeo@ual.es.
authors.forename: Amadeo R
authors.initials: AR
authors.lastname: Fernández-Alba
mesh_terms: D005638:Fruit / Q000737:chemistry*; D013058:Mass Spectrometry / Q000379:methods*; D010573:Pesticide Residues / Q000032:analysis*; D015203:Reproducibility of Results; D014675:Vegetables / Q000737:chemistry*
chemical_list: D010573:Pesticide Residues
keywords: High-resolution mass spectrometry; Multi-residue method; Orbitrap; Pesticides; Simultaneous MS/MS2