Herman Beckman

The effect of the column support material on the gas chromatographic resolution of methyl parathion, ethyl parathon, ethyl paraoxon, malathion, and malaoxon☆

Abstract The gas chromatographic capabilities of commercially available solid supports produces from diatomaceous earths were compared, using QF-1 silicone (FS 1265, 10 000 centistokes) as the stationary liquid phase. The relative efficiencies of the columns were evaluated from the chromatographic data obtained with the orga- phosphate compounds methyl parathond, ethyl parathon, ethyl paraoxon, malathion, and malaoxon. The data indicated that commericial methods for the preparation of solid supports have improved, but not to a degree sufficient to assure reproducible results with different batches of the same type of support. Each new batch of support should be examined for density and adsorptive characteristics before it is considered as a replacement for the column previously used.

Separation and detection of submicrogram quantities of pesticides by an improved TLC technique

In the last few years thin-layer chromatography has developed into one of the most important techniques available for the separation and identification of components of a mixture. It has paralleled gas chromatography in importance and period of development.