英文摘要 |
A method using commercial enzyme immunoassay kits, tube type and plastic well type, to determine carbofuran and aldicarb residues in fruits and vegetables has been developed. Samples were extracted with acetone, evaporated to dryness under nitrogen at room temperature, and redissolved in 0.02 M phosphate buffered saline for enzyme immunoassay. Recovery studies were performed at the 0.05-1.5 ppm fortification levels. Carbofuran was spiked into chopped potatoes, pe-tsais and papayas, and aldicarb into carrots, oranges and mung beans. Recoveries were between 75 and 121%. Coefficients of variation were between 1.3 and 16%. The detection limits of the pesticides in samples were in the range of 0.1 to 1.0 ppb. The cross-reactivities of 3-hydroxy carbofuran and 3-keto carbofuran to carbofuran were below 4%. The cross-reactivity of aldicarb sulfone to aldicarb was as high as 42-53%, while aldicarb sulfoxide showed relatively low cross-reaction to aldicarb. Enzyme immunoassay methods have the advantages of higher sensitivity and simpler procedure as compared to HPLC methods. The disadvantages include less reproducibility and inability to determine target pesticides and their metabolites simultaneously. Therefore, enzyme immunoassay methods are suitable for fast screening of carbofuran and aldicarb residues and can not take the place of HPLC. |