High-pressure liquid chromatographic analysis of tolbutamide in serum.

A high-pressure liquid chromatographic (HPLC) analysis of tolbutamide in serum is described. The assay requires only 1 ml of serum and is capable of measuring as little as 2 mug of tolbutamide. The metabolites of tolbutamide do not interfere in the assay. Human serum samples, taken after a 1-g oral dose of tolbutamide, were analyzed by the HPLC and an existing GLC procedure, and the results are compared.