HPLC-UV DETERMINATION OF PESTICIDE-RESIDUES AT 0.01-PPM IN APPLE AND PEAR PULP USED FOR BABY-FOOD

Two distinct methods are described for determination of residues of et hiofencarb and triforine, and of diflubenzuron, teflubenzuron, and tri flumuron at the 0.01 ppm level in apple and pear pulp used for baby fo od; recoveries are above 50 %. Diflubenzuron, teflubenzuron, and tritl umuron are extracted with a 1:1 mixture of dichloromethane and acetone , and the extracts are cleaned by SPE using C-18 as stationary phase a nd methanol as mobile phase. Ethiofencarb and triforine are extracted with dichloromethane, and the extracts cleaned using the same stationa ry phase but a 1:1 mixture of acetonitrile and water as mobile phase. Analysis of both groups of pesticides is by isocratic HPLC-UV at 210 n n using an RP-18 column and acetonitrile-water as mobile phase.