title: Validation and application of a liquid chromatography-tandem mass spectrometry based method for the assessment of the co-occurrence of mycotoxins in maize silages from dairy farms in NW Spain.
abstract: The first objective of this study was the validation of an efficient multi-analyte method for the simultaneous detection and quantification of mycotoxins in maize silage, by reverse-phase liquid chromatography coupled with electrospray ionisation triple quadrupole mass spectrometry (LC-HESI-MS/MS). A simple liquid/solid extraction was performed either with clean-up on Mycospin 400 columns or without any clean-up. Almost all the target mycotoxins showed highly-suppressed signals in the presence of a matrix, emphasising the need to quantitate mycotoxins by means of matrix-matched calibrations. An alternative validation method based on ISO 11843 and on a single factor balanced design was implemented. The achieved average recoveries from spiked samples at three levels ranged from 60% to 122% with relative standard deviations (rsd) below 11%. Limits of Detection (LODs) and Limits of Quantification (LOQs) were between 0.02-17.1 µg kg-1and 0.06-57 µg kg-1. The calculated repeatability and within-lab reproducibility ranged from 5.2 to 23.2% and from 7.2 to 23.9%, respectively. Finally, the decision limit and detection capacity, CCα and CCβ, were calculated for all mycotoxins having regulated/recommended contents in feed. The validated method was applied to 148 samples collected over two years in 19 dairy farms from Galicia (NW Spain). Of the analysed samples, 62% contained at least one mycotoxin. Zearalenone (ZEA), deoxynivalenol (DON), fumonisins B1 and B2, roquefortine C, α-zearalenol, β-zearalenol, enniatins B and B1, andrastin A, marcfortine A, verruculogen and mycophenolic acid were quantified, the highest average detection frequency being for enniatin B (51%). DON, mycophenolic acid and ZEA plus metabolites (α-zearalenol, β-zearalenol) were the most abundant mycotoxins.
authors.affiliation: a Department of Animal Production , INGACAL (Galician Institute for Food Quality) -CIAM (Agrarian and Agronomic Research Centre), Laboratory of Food/Feed Safety and Organic Contaminants , A Coruña , Spain.
authors.forename: Thierry
authors.initials: T
authors.lastname: Dagnac
authors.affiliation: a Department of Animal Production , INGACAL (Galician Institute for Food Quality) -CIAM (Agrarian and Agronomic Research Centre), Laboratory of Food/Feed Safety and Organic Contaminants , A Coruña , Spain.
authors.forename: Alicia
authors.initials: A
authors.lastname: Latorre
authors.affiliation: a Department of Animal Production , INGACAL (Galician Institute for Food Quality) -CIAM (Agrarian and Agronomic Research Centre), Laboratory of Food/Feed Safety and Organic Contaminants , A Coruña , Spain.
authors.forename: Bruno
authors.initials: B
authors.lastname: Fernández Lorenzo
authors.affiliation: b Department of Analytical Chemistry, Nutrition and Food Science. Faculty of Chemistry , Campus Vida. University of Santiago de Compostela , Santiago de Compostela , Spain.
authors.forename: Maria
authors.initials: M
authors.lastname: Llompart
mesh_terms: D002853:Chromatography, Liquid; D003612:Dairying; D000072480:Farms; D005506:Food Contamination / Q000032:analysis*; D009183:Mycotoxins / Q000032:analysis*; D012820:Silage / Q000032:analysis*; D013030:Spain; D053719:Tandem Mass Spectrometry; D003313:Zea mays / Q000737:chemistry*
chemical_list: D009183:Mycotoxins
keywords: Multi-mycotoxin method; clean-up free extraction; maize silage; mass spectrometry; monitoring; validation strategy