MULTIRESIDUE ANALYTICAL METHOD OF PESTICIDES BY GC-MS - APPLICATION OF MACROPOROUS DIATOMACEOUS-EARTH COLUMN AND SILICA-GEL CARTRIDGE

A rapid multiresidue method of pesticides using macroporous diatomaceo us earth (MDE) column and silica gel cartridge for cleanup procedure w as developed. The method was based on the experimental elution profile s of 174 compounds. The majority of pesticides were eluted with hexane and 15% acetone in hexane from the MDE column and the silica gel cart ridge, respectively. Recoveries of a large number of pesticides from e ach column were satisfactory except for a few easy hydrolyzed compound s or high polar compounds. Synthetic pyrethroids were eluted into seve ral fractions from the MDE column. The availability of the method was evaluated on recoveries from tomato fortified with 49 compounds. Mean recoveries were ranged from 48% for acephate to 133% for fenitrothion and limits of detection (LOD) were between 0.003 and 0.01 ppm.