Abstract
The use of formic acid in the carrier gas improves the gas chromatography of barbiturates. Both, the peak area and the number of theoretical plates are increased, but there is no change in the retention times of the barbiturates examined. As a result of interactions between the solid support and formic acid, adsorption of the barbiturate is reduced considerably when formic acid is present in the carrier gas. In contrast, after withdrawal of formic acid, all barbiturates with the exception of N-alkylated derivatives are removed by the column-due to increased adsorption on the support material. A possible mechanism is discussed. © 1974 Friedr. Vieweg & Sohn, Verlagschesellschaft mbH.