Determination of imidacloprid in vegetables by high-performance liquid chromatography with diode-array detection.

An HPLC method is described for the determination of imidacloprid residues in vegetables at levels ranging from 0.01 to 0.60 mg/kg. The selection of the extraction and clean-up procedure is discussed. Spectral data obtained with diode-array detection allow the identification of imidacloprid residues. Thermospray mass spectrometric studies were carried out in combination with HPLC. The mean recoveries and standard deviations were 95% and 4.7%, respectively, in the various crops tested. Registration of the analytical results for a control sample in quality control charts demonstrated the performance of the method. Data for incurred residues of imidacloprid in vegetable samples routinely applying the proposed method are also presented.