Development of a direct competitive enzyme-linked immunoassay for carbofuran in vegetables

Three ELISA formats, antigen coated, antibody coated and the second antibody coated for the determination of carbofuran were investigated with conjugations including hapten-BSA, hapten-OVA, hapten-HRP and anticarbofuran IgG-HRP. Results showed that the second antibody-coated method of ELISA had a better performance in the establishment of standard curves and detection of carbofuran residue in vegetables samples. The sensitivity for detection, the 150 value was 36.1 ng/ml at a practical working concentration range from 3.44 to 380.1 ng/ml and the limit of detection for carbofuran was 3.44 ng/ml. The average recoveries of determination for carbofuran spiked in cabbage, lettuce, carrot, winter fragrant-flowered garlic, bamboo shoot and green soy bean were 85.24%, 101.8%, 103.6%, 90.52%, 106.9% and 94.08%, respectively. Additional analyses confirmed that the results given by the ELISA method was in agreement with those of the gas chromatography (GC) method. (C) 2007 Elsevier Ltd. All rights reserved.