Abstract:

The pretreatment procedure of enzymatic hydrolysis and extraction coupled with solid phase extraction(SPE) purification is usually employed for the determination of β-agonists by high performance liquid chromatography(HPLC) with tandam mass spetroscopy(MS) in food originated from animals. In this study, a HPLC-MS/MS with QuEChERS(Quick, Easy, Cheap, Effective, Rugged, Safe) purification procedures was developed for the determination of terbutaline, salbutamol, ractopamine and clenbuterol in food of animal origin using both acid hydrolysis extraction method and enzymatic hydrolysis extraction method in food poisoning event caused by clenbuterol and analogs. Using enzymatic hydrolysis extraction with QuEChERS purification and electrospray ionization mass spectrometry in positive mode adopting multiple reaction monitoring(MRM) mode, four analytes were analyzed in the range of 1.0~20.0 μg/L with correlation coefficients(R) higher than 0.999. The limit of detection(LOD) and the limit of quantification(LOQ) was 0.1 μg/kg and 0.3 μg/kg, respectively, and recoveries for 4 β₂-agonists in pork and beef samples ranged from 78.5% to 112% with relative standard deviation(RSD) of 2.8%~8.9%. When acid hydrolysis extraction was used alternatively, the pretreatment time was shortened greatly, but the result for ractopamine was slightly lower than that using the enzymatic hydrolysis extraction procedure. The combined use of two pretreatment procedures will promote the emergency response in real food poisoning case caused by clenbuterol and analogs.

Key words: β₂-agonist, acid hydrolysis extraction method, enzymatic hydrolysis extraction method, QuEChERS, high performance liquid chromatography-tandem mass spectrometry, isotope internal standard