Solid phase extraction chemiluminescence determination of methamidaphos on vegetables

The determination of the methamidaphos pesticide residue on vegetables with a simple solid phase extract(SPE) flow injection(FI)-chemiluminescence(CL) method is described. The method is based on the enhancing effect of methamidaphos on the CL reaction of luminol with hydrogen peroxide in an alkaline solution. Under the optimal conditions, the CL intensity is linear to the methamidaphos mass concentration in a range of 0.2-13 mu g/mL (r = 0. 9992). The detection limit(3 sigma,) is 0.047 mu g/ml,. The relative standard deviations for the analysis of three samples are 1.8%, 2.5% and 3.7% (n = 5), respectively. The recovery is in a range of 90%-109% by the method. In this work, this method was successfully applied to the determination of the methamidaphos residue on some vegetable samples.