Xiaojia Huang,Linli Chen,Meng Chen,Dongxing Yuan,Shuyu Nong.Journal of Separation Science, 2013. 36: 907-915.

In the present study, a convenient and sensitive method for determination of six penicillinantibiotics (amoxicillin, ampicillin, penicillin G, oxacillin, cloxacillin, and dicloxacillin)in milk and honey samples was developed. Milk and honey samples were diluted withwater, then directly treated by stir bar sorptive extraction based on poly (vinylimidazoledivinylbenzene)monolithic material as coating. The analytes were analyzed by LC/ESIMS/MS. Several extraction parameters including extraction and desorption time, pH value,and ionic strength in sample matrix were investigated in detail. Under the optimized extractionconditions, the calculated detection limits for the target compounds were as lowas 0.23–2.66 ng/kg in milk and 0.18–1.42 ng/kg in honey, respectively. Good linearity wasobtained for analytes with the correlation coefficients (R2) above 0.997. Excellent methodreproducibility was achieved in terms of intraday and interday precisions, indicated by theRSDs of <5 .0 and <10.0%, respectively. finally, the proposed method was successfullyapplied to the determination of penicillin antibiotics residues in different milk and honeysamples.