Although morphine may be gas chromatographed as such, its phenolic properties cause adsorption which produces tailing and makes quantitative work impossible. This difficulty was overcome by converting morphine to its trimethylsilyl ether which gave a symmetrical elution The alkaloids of opium were extractex and morphine separated from nonphenolic alkaloids by ion-exchange resins. The morphine fraction was allowed to react with hexamethyldisilazane, tetraphenylethylene was added as the internal standard, and the solution was gas chromatographed on a column of silicone rubber SE-30.
eak suitable for quantitative estimation.
URING THE PAST few years, the gas chromatographic method has become increasingly important for analysis of high molecular weight compounds of biological origin. In 19130 Lloyd, et al. (l), gas chromatographed 33 different alkaloids, including the major alkaloids of opium at temperatures slightly above 200'. Eddy, et al. ( 2) , used gas chromatography for the determination of the origin of opium based on the peak height ratios of several of the major alkaloids.
When working with alkaloids on low-loaded columns, tailing can often cause considerable difficulties. The support material will contain active spots which will not be sufficiently covered by the stationary liquid to prevent adsorptive effects. Adsorption can be reduced to a great extent if the support material is washed with acid and alkali and treated with dichlorodimethylsilane (3), hexamethyldisilazane (4), and/or a surface-active agent (4-6). Phenolic alkaloids, such as morphine, are difficult to gas chromatograph even on a treated support. If adsorption takes place, it will affect the retention time as