Determination Of ?-agonists In Hair And Urine Of Swine,Bovine And Sheep By UPLC-MS/MS

?-agonists is a class of chemical analogues of epinephrine,when used at high doses for a long period of time,can increase the lean body mass of the carcass,increase weight gain,and increase feed conversion rates,resulting in a reduction in the proportion of animal fats.In 1980 s,?-agonists was used as a growth promoter for animal production.Human consumption of animal foods containing ?-agonists poses a health risk.Since 1988,the European Union and the United States have banned the use of in livestock and poultry,and the 235 announcement of Chinese Ministry of Agriculture have announced that ?-agonists must not be found in all edible tissues.UPLC-MS/MS method was used for the simultaneous determination of 16 ?-agonists,containing arformoterol,bambuterol,brombuterol,cimaterol,cibuterol,clenbuterol,clenproperol,clorprenaline,formoterol,mabuterol,ractopamine,salbutamol,tebutaline,tulobuterol,zilpaterol,phenylethanolamine A in hair and urine of swine,bovine and sheep.Swine,bovine and sheep hair samples were digested with 1 mol/L NaOH and extracted by ethyl acetate/isopropanol(40:60,v/v),purificated with MCX solid-phase extraction column,reconstituted with 1 mL 0.1% formic acid water-methanol(95:5,v/v),with 0.1% formic acid water-methanol solution containing 0.1% formic acid as mobile phase,separation with Agilent ZORBAX SB-Aq column,detection in positive ion scan,multiple reaction mode,quantification using internal standard method.The detection limit of 16 ?-agonists in hair was 0.2~2 ng/g,and the limit of quantification was 0.5~5 ng/g.The linearity was good in the range of 5~500 ng/g,R>0.99.The recoveries at the three levels of low,medium and high concentrations were 67.1% to 115.8%,the intra-assay coefficient of variation was 1.1% to 13.6%,and the inter-assay coefficient of variation was 2.4% to 14.4%.The method has good stability and high sensitivity,and meets the multi-residue testing requirements of veterinary drugs.Swine,bovine and sheep urine was hydrolyzed with ?-glucuronosyl/arylsulfatase,extracted with 6% ammonia-ethyl acetate/isopropanol(6:94,v/v),purification with MCX solid-phase extraction column,elution with 5% ammonia in acetonitrile,nitrogen evaporation at 50°C,1 mL of 0.1% formic acid water-methanol(95:5,v/v)reconstitution.The above liquid-phase mass spectrometry conditions were used to separate and detect 16 ?-agonists.The detection limit of 16 ?-stimulants in urine was 0.05~0.3 ng/mL,and the limit of quantitation was 0.1~0.5 ng/mL.The linearity of the method was good in the range of 0.1~20 ng/mL,R>0.99.The recoveries were 62.9%~115.7% at low,medium and high levels of three concentrations;the intra-assay coefficient of variation was 0.8% to 13.2%,and the inter-assay coefficient of variation was 2.8% to 14.9%.The method has good stability and high sensitivity,and satisfies the requirements for the multi-residue detection of ?-agonist drugs in urine of swine,bovine and sheep.