Analytical methods for the determination of pesticide residues using gas chromatograghy with nitrogen-phosphorus detector

The analysis methods for 3 pesticides (ametryn, cyanophos, and fonofos) were developed and validated. One 1,3,5-triazine herbicide (ametryn), and 2 organophosphorus insecticides (cyanophos and fonofos) were tested. Three kinds of residual pesticides were classified into 2 groups according to the chemical structure and separation method. Solid-phase extraction (SPE) cartridge was used for sample purification and isolation of analytes. Final solution was analyzed with GC with nitrogen-phosphorus detection (NPD). Confirmation analysis of pesticides was carried out by GC-MS in the selected ion monitoring (SIM) mode. Correlation coefficient was ranged from 0.999 to 1.0, depending on sample analytes. Rice, apple, and soybean samples were selected for recovery experiment. Overall recovery rates from blank samples spiked at 3 fortification levels ranged from 76.29 to 107.4% with relative standard deviations lower than 20.2%. The limit of quantification was < 3-5 mu g/L depending on the analytes, and the reporting level of the method, defined as lower than the maximum residue levels established by Korea Food & Drug Administration (KFDA).