UHPLC-MS/MS Determination of Residual Amounts of 9 Anticoagulant Rodenticides in Foodstuffs

Foodstuff sample was extracted with acetonitrile, and the extract obtained was purified by passing through Florisil SPE column. The eluate obtained was determined and identified by HPLC-MS/MS. Mixtures of methanol and 10 mmol·L-1 ammonium acetate solution of various ratios were used as mobile phase in gradient elution and electrospray ionization source with negative ionization mode as well as multiple reaction monitoring mode were used in the MS/MS analysis. Values of detection limit (3S/N) found were 0.38 μg·kg-1 for difethialone and 0.08 μg·kg-1 for the remainder of 8. Tests for recovery were made by addition of standard rodenticide solutions at 3 different concentration levels to blank foodstuff sample matrixes, values of recovery found were in the range from 55.3% to 118.1%, with RSD′s (n=6) in the range from 2.2% to 14.8%.