The Development Of Standard Substance Clenbuterol In Lyophilized Pig Urine

Clenbuterol hydrochloride, commonly known as "lean", is a syntheticbeta-adrenergic receptor agonist, which is used for feed additive owing to promotinganimal growth, improving feed conversion efficiency and meat quality remarkably.As a series food poisoning issues with "lean" consumption of animal source wasexposed, many countries in the world, including China, have forbidden clenbuterol tobe used in the aquaculture industry legally. However, due to some reasons includingthe drive by economic interests, difficult detection, and insufficient understanding ofthe dangers to people, illegal abuse still occurs widely in many countries. At present,the forcible detection of ante-mortem urine of live specimens is very significant andeffective means for the safety supervision of animal origin foods, so clenbuterolresidue testing has become an obligatory item for the pigs before slaughter.The preparation of clenbuterol standard material in lyophilized powder of pig urineand evaluation are investigated in this paper. A set with five concentrations levels ofclenbuterol (CLB) standard substances in pig urine freeze-dried powder wasdeveloped, while taking urine of healthy and safe pig for the blank matrix and CLBbeing spiked into the urine. The uniformity and stability testing for the standardmaterials are carried out by using liquid chromatography-tandem mass spectrometryin eight laboratories, and the uncertainty of the testing is evaluated. The result showsthat the uniformity of the set of standard materials is very good, and the storagestability is more than1year at4℃. The5concentrations of clenbuterol in standardsubstance and corresponding uncertainty test results are as follows: less than0.10ng/mL (blank swine urine lyophilized powder),(0.65±0.15) ng/mL,(1.28±0.44)ng/mL,(3.78±0.46) ng/mL and (11.48±1.72) ng/mL,(k=2). As clenbuterol carrierof traceability in the pig urine, the set of standard material can be applied to themethod validation and quality control of clenbuterol detection in pig urine.