title: Combined target and post-run target strategy for a comprehensive analysis of pesticides in ambient air using liquid chromatography-Orbitrap high resolution mass spectrometry.
abstract: A comprehensive strategy for the analysis of current airborne pesticides has been developed using liquid chromatography coupled to high resolution mass spectrometry. The methodology includes both quantitative target analysis and post-run target screening analysis. The quantitative method was validated after a previous statistical optimisation of the main factors governing the ion source ionization and a study of the single-stage Orbitrap fragmentation through the HCD cell. The quantitative method presented recoveries ranging from 73 to 116%, with precision (RSD) lower than 20%, for the 35 substances in the scope of the target method. The full-scan accurate mass data were acquired with a resolving power of 50000 FWHM (scan speed, 2 Hz), and alternating two acquisition events, ESI+ without fragmentation and ESI+ with fragmentation. The method-LOQ was 6.5 pg m(-3) for most of the target pesticides. For post-target screening a customized theoretical database, that included pesticides, metabolites and other substances such as emerging flame retardants was built up. For identification, accurate exact mass with less than 5 ppm, and some diagnostic ions including isotopes and/or fragments were used. The strategy was applied to ten samples collected in a rural area of Valencia (Spain). Four pesticides, namely carbendazim, metalaxyl, myclobutanil and terbuthylazine, were detected in concentrations from 16 pg m(-3) to 174 pg m(-3). Some pesticides and metabolites (endothal, fenfuram, terbuthylazine-2-OH), in addition to two flame retardants were tentatively identified in the post-run target screening analysis.
authors.affiliation: Public Health Laboratory of Valencia-FISABIO, 21, Avenida Catalunya, 46020 Valencia, Spain.
authors.forename: Clara
authors.initials: C
authors.lastname: Coscollà
authors.affiliation: Public Health Laboratory of Valencia-FISABIO, 21, Avenida Catalunya, 46020 Valencia, Spain.
authors.forename: Nuria
authors.initials: N
authors.lastname: León
authors.affiliation: Analytical Chemistry Department, Universit of Valencia, Edifici Jeroni Muñoz, Dr. Moliner 50, 46100 Burjassot, Spain.
authors.forename: Agustín
authors.initials: A
authors.lastname: Pastor
authors.affiliation: Public Health Laboratory of Valencia-FISABIO, 21, Avenida Catalunya, 46020 Valencia, Spain; Analytical Chemistry Department, Universit of Valencia, Edifici Jeroni Muñoz, Dr. Moliner 50, 46100 Burjassot, Spain. Electronic address: yusa_vic@gva.es.
authors.forename: Vicent
authors.initials: V
authors.lastname: Yusà
mesh_terms: D000393:Air Pollutants / Q000032:analysis*; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D013058:Mass Spectrometry / Q000379:methods*; D008970:Molecular Weight; D010575:Pesticides / Q000032:analysis*; D013030:Spain
chemical_list: D000393:Air Pollutants; D010575:Pesticides
keywords: Ambient air; DoE; High-resolution mass spectrometry; Orbitrap; Pesticides