Determination Of Clenbuterol In Pork By Solid Phase Extraction Coupling Ultra Performance Liquid Chromatography-Tandem Mass Spectrometry

As the fast development of economy, food safety has become a hot topic of public health. Clenbute (CL) hydrochloride is a kind of beta Adrenalin. They are generally added to the feed, and used to lean meat ratio. In this work, a method for determination of CL in pork samples using solid phase extraction and ultra performance liquid chromatography coupled with electrospray tandem mass spectrometry (SPE-UPLC-MS) has been developed and successfully applied to survey target CL in Lanzhou farmers'markets and free markets.1. Establishment of detection method for CL using ultra performance liquid chromatography coupled with electrospray tandem mass spectrometry. The separation was performed on a Waters Acquity UPLC TM BEH C18 column with gradient elution using methanol and 0.1%formic acid at a flow rate of 0.25mL/min.Under multiple reaction monitoring mode (MRM), the effects of MS parameters, such as capillary voltage and collision energy were investigated and optimized. Under the optimized conditions, the detection limits of CL reached 0.1μg/L. The correlation coefficient was 0.9998.2. Development of accelerated solvent extraction and solid phase extraction method for extraction of CL in pork samples. ASE extracted CL from samples as follows: temperature:50℃, pressure:1500psi, heating:6min, cycles twice. The enrichment and cleanup effects of three different types of SPE cartridges were compared, and various influential factors such as flow rate, the elution solvent and volume, pH of samples were investigated. The concentration and purification was performed using Qasis MCX. Under the optimized conditions, recoveries and relative standard deviations (RSD, n=3) at0.2μg/L,1.0μg/L and 10.0μg/L spiking levels were 78.5%～98.6%, 2.9%～4.3%. The proposed method could meet the requirement for detecting CL in pork.3. Distribution survey of CL in pork meat and viscera of three countries and five zone in Lanzhou city. The existence and distribution of CL in pork and viscera were surveyed in November 2008 and May 2009 from 24 free markets using the established SPE-UPLC-MS-MS method. Results indicated that the residues of CL were detected in all of Honggu, Gaolan, Yazhong and Yongdeng zeros. The ratio of detection was 33.3%. The quality of pork had been improved in 2009. The ratio was decreasing at 8.3%. The residues of CL in liver were the highest in viscera.