Gas-liquid chromatographic screening method for six synthetic pyrethroid insecticides.

A method was developed for simultaneously determining 6 synthetic pyrethroid insecticides (fenpropanate, tetramethrin, permethrin, cypermethrin, fenvalerate, and deltamethrin) in apple, orange, grape, lemon, tomato, green pepper, and paprika, and sugar beet root and leaves. The pesticides were extracted with acetone and partitioned into methylene chloride. The extract was purified by column chromatography on active carbon-magnesia-diatomaceous earth and then on alumina. Analysis by gas-liquid chromatography with 63Ni electron capture detection was completed in 6 min on a 3% SE-30 liquid phase, using a short column. Recoveries from fortified samples ranged from 68 to 89% in the range of 0.3-1.0 ppm and from 67 to 83% in the range of 0.02-0.2 ppm.