Investigation of colloidal gold immunochromatographic strip for quantitative determination of variety of β-agonists in swine urine

In this study,the colloidal gold was obtained by reducing gold chloride with sodium citrate. Then,the colloidal gold and beta- agonists monoclonal antibody was conjugated.By optimized experimental parameters with chessboard titration method and single factor experiment,a method for Colloidal gold immunochromatographic quantitative detection of variety of beta- agonists in swine urine was established. The results showed that the method exhibited dynamic linear range( IC_(20)~IC_(80)) for the detection of clenbuterol( CL) from 0.31 μg /L to 4.52 μg /L,with the median inhibitory concentration( IC_(50)) of 1.18 μg /L,the limit of detection( LOD,IC_(10)) was 0.14 μg /L.Samples were detected directly without treatment,the detection time was only 8 min for each sample.The result showed that the developed method had cross reaction rate with salbutamol,mabuterol,brombuterol,cimaterol,clorprenaline and other beta- agonists,which could achieve multiresidue determination of beta- agonists. In the negative swine urine sample standard addition recovery experiment,the recoveries for intra- assay ranged from 83.6% to 102.2%and inter- assay ranged from 84.2% to 101.5%,and the relative standard deviation of intra- assay and inter- assay were both less than 10%. The comparison experiment with ELISA and HPLC / MS tests showed that the test strip could be used in the multiresidue determination of beta- agonists in swine urine.