Abstract:

In order to detect trace clenbuterol in swine urine, a method was developed by liquid chromatography tandem mass spectrometry with dispersive solid phase extraction using molecular imprinted polymer as adsorbent. The samples were absorbed by molecularly imprinted polymer. After eluted with methanol/acetic acid/water (7/2/1), the eluate was evaporated to dryness under a nitrogen stream and dissolved in 0.1% formic acid water/methanol (9/1). The extract was filtered through 0.22 μm filter, and 5 μL filtrate was injected into LC-MS/MS for analysis. The experiment results showed that MIP had specific recognition selectivity, excellent binding affinity and elution property for clenbuterol. Good linearity was obtained for clenbuterol at the concentration of 0.2-25 μg/L with correlation coefficient of 0.9992. The detection limit(S/N=3) and quantification limit(S/N=10) of the proposed method for clenbuterol was 0.08 μg/L and 0.2 μg/L. The recoveries of clenbuterol in swine urine at 0.2, 1.0, 2.0 μg/L were above 70.2% with the relative standard deviation of less then 4.16%. The method was reliable, sensitive, reproducible, less reagent dosage and no matrix interference, so it could meet the requirement for determination of the clenbuterol in swine urine.