Study On The Detection Technology Of β-agonists Residue In Foodstuffs Of Animal Origin For Import And Export

The aim of the paper was to simultaneously detect ten β-agonists including ritodrine tulobuterol, clenbuterol, terbutaline, salbutamol, clenpenterol, DL-isoprenaline, fenoterol, bromobuterol and ractopamine in animal origin tissues (pork, beef, pig liver, pig kidney) by GC-MS detection method.Ten β-agonists in samples was extracted with the weak acid sodium acetate buffer solution of pH5.2through the ultrasound-assisted extraction technology, protein precipitated by perchloric acid, and then adjust pH value to10±0.2, using NaCl to salt out impurities and using ethyl acetate:isopropyl alcohol (60:40) and tert-butyl ether:isopropanol (5:1) two kinds mixed solvent to extract, for further clean-up, solution was purified by mixed exchange Strata-X-C stationary phase cation column and column was eluted by5%ammonia water containing organic solvents. Finally the ten β-agonists were derivatized with100μL BSTFA:TMCS (99:1) reagent.GC-MS was operated in selected ion mode, The GC column was HP-5MS (5%phenyl methyl polysiloxane) capillary of30m×0.25mm×0.25μm, with high purity He (99.999%and above)as the carrier gas and constant flow1.0mL/min, the pressure at11.6psi, splitless injection volume2μL, injection port temperature220℃, transmission line temperature was280℃. Temperature-programmed conditions are as follows:initial temperature70℃for1min, and heated up to200℃at a rate25℃/min and maintained for6min, then to280℃at25℃/min and maintained for5min. Quadrupole temperature was150℃, solvent delay was6min, analysis time is20.4min.The results showed that this method can be developed to analyze the β-agonists in pork, beef, pig liver and pig kidney effectively, the target compounds in a wide density range are satisfactory linearity, R2reached0.9964～0.9998, when the spiked level is1～50μg/kg, the overall recoveries were between59.1～77.4%and the coefficient of variation were0.87～6.96%. The method detection limits were0.5～2.5μg/kg for all β-agonists, the method can be sensitive, accurate qualitative and quantitative to the samples.