High-performance liquid chromatographic determination of fenbutatin oxide and its persistence in peaches and nectari¬nes

A new, rapid high-performance liquid chromatographic method for the determination of fenbutatin oxide has been developed and used to study residue persistence in peaches and nectarines. The pesticide was determined in fruits on an ODS 2 column using methanol/HCl 10(-3) M 93:7 (v:v) plus NaCl (0.3 g/L) as the mobile phase, at the flow of 1.0 mL/min and detected at 205 nm. Under these conditions the detection limit was 0.05 ppm. Recoveries were 90.6-101.3% from peaches and nectarines spiked at 0.05, 1.00, and 5 ppm levels' The persistence of fenbutatain oxide residue on field and greenhouse peaches and nectarines was studied. During the experiment the decline in residue concentration was mainly caused by the dilution effect due to the increase in weight of the fruits. The high stability of this pesticide renders the effects of the environment on the decay rate of the residues negligible.