Rasmussen, Rie Romme2; Storm, Ida Marie Lindhardt Drejer4; Rasmussen, Peter Have2; Smedsgaard, Jørn2; Nielsen, Kristian Fog5
1 Division of Food Chemistry, National Food Institute, Technical University of Denmark2 National Food Institute, Technical University of Denmark3 Center for Microbial Biotechnology, Department of Systems Biology, Technical University of Denmark4 Department of Systems Biology, Technical University of Denmark5 DTU Metabolomics Core, Department of Biotechnology and Biomedicine, Technical University of Denmark
This paper describes a method for determination of 27 mycotoxins and other secondary metabolites in maize silage. The method focuses on analytes which are known to be produced by common maize and maize-silage contaminants. A simple pH-buffered sample extraction was developed on the basis of a very fast and simple method for analysis of multiple pesticide residues in food known as QuEChERS. The buffering effectively ensured a stable pH in samples of both well-ensiled maize (pH7). No further clean-up was performed before analysis using liquid chromatography-tandem mass spectrometry. The method was successfully validated for determination of eight analytes qualitatively and 19 quantitatively. Matrix-matched calibration standards were used giving recoveries ranging from 37% to 201% with the majority between 60% and 115%. Repeatability (5-27% RSDr) and intra-laboratory reproducibility (7-35% RSDIR) was determined. The limit of detection (LOD) for the quantitatively validated analytes ranged from 1 to 739 mu g kg(-1). Validation results for citrinin, fumonisin B-1 and fumonisin B-2 were unsatisfying. The method was applied to 20 selected silage samples and alternariol monomethyl ether, andrastin A, alternariol, citreoisocoumarin, deoxynivalenol, enniatin B, fumigaclavine A, gliotoxin, marcfortine A and B, mycophenolic acid, nivalenol, roquefortine A and C and zearalenone were detected.
Analytical and Bioanalytical Chemistry, 2010, Vol 397, Issue 2, p. 765-776