Monitoring of the insecticide trichlorfon by phosphorus-31 nuclear magnetic resonance (31P NMR) spectroscopy

Trichlorfon is an organophosphorus insecticide, which is extensively being used for protection of fruit crops. Trichlorfon is a thermal labile compound, which cannot be easily determined by gas chromatography (GC) and has no suitable group for sensitive detection by high performance liquid chromatography (HPLC). In this study, a P-31 nuclear magnetic resonance (P-31 NMR) has been described for monitoring of trichlorfon without any separation step. The quantitative works of P-31 NMR spectroscopy has been performed in the presence of an internal standard (hexamethylphosphoramide). Limit of detection (LOD) for this method has been found to be 55 mg L-1, without any sample preparation, and the linear working range was 150-5500 mg L-1. Relative standard deviation (R.S.D.%) of the method for three replicates within and between days was obtained <= 9%. The average recovery efficiency was approximately 99-112%. This method was applied for monitoring trichlorfon in a commercial insecticide sample and tomato sample. (c) 2006 Elsevier B.V. All rights reserved.