Determination of pesticide residues in rice grain by solvent extraction, column cleanup, and gas chromatography-electron capture detection.

A simple, easy, cheap and efficient analytical method for determination of multiple pesticide residues including organochlorine, organophosphorus, synthetic pyrethroids and herbicides in rice grain by capillary gas chromatography is developed. The quantification of residues was done by capillary gas chromatography with a μ-ECD detector and a HP-5MS capillary column. Known amounts of a mixture of pesticides were added to grain prior to extraction, cleanup and GC-determination. Recoveries were checked at two fortification levels; 0.1 and 0.5 μg/g. Qualitative and quantitative analysis were carried out based on the retention time and peak area basis. The results show that the average recovery of the analytical method for the fortified rice samples was in the range of 74%-111% and %RSD in the range of 2.41-12.42. The analytical method was used to analyze commercial rice grain samples.