Determination of carbofuran residue in sugarcane by direct competitive enzyme-linked immunosorbent assay

The method of antibody-immobilized direct competitive ELISA was employed to determine carbofuran residue in sugarcane.Under the optimized conditions,the liner concentrations ranged from 0.000 1 mg/L to 1 mg/L,the IC50 value was 3.09 μg/L with relative standard deviation (RSD) of 9.3%,IC20 value was 0.085 μg/L.The recoveries were 86.3%-99.1%,89.0%-101% and 70.7%-90.6% with the RSD of 5.4%,5.2% and 10.7% at the spiked level of 1,0.1 and 0.01 mg/kg in sugarcane.The limit of detection of ELISA was 6.30×10-11 g and the limit of quantification(LOQ) was 1.26 μg/kg for carbofuran residue in sugarcane.With the above similar sample preparation procedure,the limit of detection of HPLC-UVD was 5.00×10-8 g and the limit of quantification for carbofuran residue in sugarcane was only 2.5 mg/kg.