Istituto Zooprofilattico Sperimentale dell'Umbria e delle Marche ''Togo Rosati''

Authors   Moretti S, Lega F, Rigoni L, Saluti G, Giusepponi D, Gioiello A, Manuali E, Rossi R, Galarini R

Abstract  A multiclass screening method to detect fifty-three forbidden substances by liquid-chromatography coupled to hybrid high-resolution mass spectrometry (LC-Q-Orbitrap) was developed and validated in bovine bile and urine. Eight classes of compounds were included in the method's scope (β-agonists, corticosteroids, nitroimidazoles, progestins, resorcylic acid lactones (RALs), sedatives, steroids and stilbenes) plus chloramphenicol and dapsone. After hydrolysis, the sample was divided in two aliquots, which followed two parallel purification steps. The reunified extracts were injected and two chromatographic runs performed in positive and negative ionization mode, respectively. The validation data (60 different samples per matrix) proved that the method was fit for purpose with detection capabilities lower than 1 μg L^-1 in both matrices. The combined application of accurate mass acquisition and two-stage mass spectrometry (parallel reaction monitoring) was crucial to achieve suitable selectivity, which is the most critical parameter mainly for urines. Finally, the long-standing problem of the high rate of false positive results for RALs, due to the natural ingestion of mycotoxin, zearalenone, was taken on including all their labelled standards. That allowed a very satisfactory management of this screening test.

Publish Date  2018

Volume   1032

ISSN  1873-4324

DOI  doi.org/10.1016/j.aca.2018.06.037

URL   https://www.sciencedirect.com/science/article/pii/S000326701830802X?via%3Dihub

Journal   Analytica Chimica Acta

Pages   56-67

PMID    30143222