Analysis of solvent residues in pharmaceutical bulk drugs by wall-coated open tubular gas chromatography.

A simple general method for the determination of solvent residues in drugs is described. The procedure is based on wide-bore wall coated open tubular (WCOT) gas chromatographic analysis of bulk drug solutions. The use of wide-bore WCOT columns with chemically crosslinked methyl silicone stationary phases offers improvements in specificity and sensitivity over earlier packed-column methods. The factors that influence method accuracy are discussed, including a consideration of instrumental and matrix contributions to the linearity and bias of the method. Some problems with interferences peculiar to benzyl alcohol are reported.