Several investigators have reported that ascorbic acid can be analyzed by gas-liquid chromatography (GLC) following conversion of the parent compound to its trimethylsilyl ether (l-5). We have applied this procedure to the analysis of ascorbic acid in tissues and in this report describe the technique we have developed. The method is suitable for microanalytical work and has the advantage that several other carbohydrates and carbohydrate derivatives can be measured simultaneously in the same extract. The results presented are based on work with brain samples, but our preliminary data show that the technique can be applied to other tissues as well.
MATERIALS AND METHODS
Chemicals
All reagents and standards were of reagent grade. Ascorbic acid was obtained from Sigma Chemical Co., sorbitol from Fisher Scientific Co., and hexamethyldisilazane (HMDS) and trimethylchlorosilane (TMCS) from Applied Science Laboratories. Pyridine was stored over molecular sieve 5A (Linde Corp.).
Tissues
Brains were obtained from Holtzman rats. The adult values were determined on male animals that were 60 to 90 days old. Neonatal animals were not sexed since the sex difference in rat brain ascorbic acid levels is not evident until after 42 days of age (6).