[Simultaneous determination of multiresidual pesticides in vegetables and fruit by high performance liquid...

A high performance liquid chromatographic (HPLC) method for simultaneous determination of 12 pesticides in vegetable and fruit samples was developed and evaluated. The analytical procedure involved in ultrasonic extraction with ethyl acetate, purification using a Florisil SPE column (6 mL, 1000 mg) and n-hexane-dichloromethane (1 : 1, v/v). The eluate was blown to dryness under a stream of nitrogen and the residue was dissolved in 0.10 mL of methanol, followed by separation and quantitative analysis by using reversed-phase HPLC with gradient elution for the baseline separation of the 12 pesticides and programmed ultraviolet wavelength shift detection in 32 min. The detection limits of the 12 pesticides ranged from 0.14 to 2.65 ng. The average recoveries ranged from 62.2% to 118.2% with the relative standard deviation (RSD) range of 0.56%-11.8% for the spiked fruit samples, and from 52.1% to 124.6% with RSD range of 0.89%-18.4% for the spiked vegetables. The method was applied to determining multiresidual pesticides in vegetables and fruit for a total of 40 samples. It is concluded that this method is rapid, accurate, sensitive and reproducible for determining trace pesticides in vegetable and fruit samples.