Independent Laboratory Method Validation and Determination of Spiromesifen Residues in Tomatoes

A simple and inexpensive method was developed using solidphase extraction, together with high performance liquid chromatographic method with PDA detection for determination of spiromesifen residues. The evaluated parameters include the extracts by ChemElut ® CE 1020 column using cyclohexane/ethyl acetate (85/15, v/v) mixture and acetonitrile solvents. The method was validated using tomato fruit samples spiked with spiromesifen at different fortification levels (0.05 and 0.5 µg/g). Average recoveries (using each concentration six replicates) ranged 84�94%, w ith relative standard deviations less than 2%, calibration solutions concentration in the range 0.05�10.0 µg/mL and limit of detection (LOD) and limit of quantification (LOQ) were 0.02µg/g and 0.05µg/g respectively. Finally the tomato fruit residue samples were re analyzed by HPLC.