ECD-Gas Chromatographic Determination of Pyrethroid Insecticides in Grains

Gas-liquid chromatographic determination

A method for the determination of total bile acids in human feces that is suitable for routine application is described and discussed. Bile acids are extracted from freezedried feces with acetic acid and toluene, in the presence of the i?ternal standard 23-nordeoxycholic acid. After saponification of the extract, bile acids and the internal standard are methylated and converted by mild chromic ...

Gas chromatographic determination of deoxynivalenol in wheat.

Modifications to a published method are described for the determination of deoxynivalenol (DON) in wheat by gas chromatography with electron capture quantitation of the heptafluorobutyrate derivative. In the modified method, DON is extracted by shaking the sample with methanol-water on a wrist-action shaker, followed by filtration through rapid flow paper. One concentration step is eliminated, ...

Sensitization risk of pyrethroid insecticides.

Pyrethrum flowers and pyrethroid insecticides.

The natural pyrethrins from the daisy-like flower, Tanacetum or Chrysanthemum cinerariifolium, are nonpersistent insecticides of low toxicity to mammals. Synthetic analogs or pyrethroids, evolved from the natural compounds by successive isosteric modifications, are more potent and stable and are the newest important class of crop protection chemicals. They retain many of the favorable propertie...

Gas-chromatographic determination of urinary oxalate.

We describe a simple, rapid method for determining urinary oxalate: isolation by precipitation with calcium chloride and conversion to dimethyl oxalate, which then is measured by gas chromatography. To each sample, tracer amounts of 14C-labeled oxalic acid are added, to determine the analytical recovery of urinary oxalate. Analytical recovery of [14C]oxalic acid added to urine specimens ranged ...