UHPLC-MS/MS Determination of Residual Amounts of 9 β2-Recepter-Agonists in Food of Animal Origin with Solid Phase Extraction

UHPLC-MS/MS with solid phase extraction (SPE) was applied to the determination of residual amounts of 9 β2-recepter agonists in food of animal origin. The sample was pulped with NH4OAc buffer solution (pH 5.2) and hydrolyzed with mixed solution of β-glucuronidase and aryl sulfatase. The hydrolyzate was centrifuged and the supernatant was purified by passing through PCX SPE column. The column was eluted with a mixture of aq.NH3-CH3OH (5+95). The eluate was evaporated to dryness by N2-blowing, and the residue was dissolved with the solution of mobile phase (B). The solution obtained was separated by using waters Atlantis dC18 column as stationary phase and mixtures of (A) acetonitrile and (B) 5 mmol·L-1 NH4OAc solution (containing 0.1% by volume of formic acid) in various ratios as mobile phase in the gradient elution. ESI+ was adopted in MS/MS. Linearity ranges of the 9 compounds were found in the same range within 10.0 μg·L-1 with the same lower limits of determination (10S/N) of 0.5 μg·kg-1. Tests for recovery were made at 3 concentration levels, giving values of recovery in the range of 70.2%-120% with RSD′s (n=6) in the range of 3.8%-19%.