Carboxylic acids in plasma or serum can be conveniently determined by capillary gas chromatography (GC) following treatment with ethyl chloroformate (ECF). The mixed organic solvent used for plasma deproteinization is also suitable as medium for the subsequent reaction step. Thus, isolation of the compounds of interest is not necessary. Before treatment of the supernatant with ECF, the neutral lipids and amino acids are removed easily by hexane extraction and cation-exchange chromatography. Ketocarboxylic acids do not require a preliminary oximation. Capillary columns with a length of 15 m and a polar silicone phase proved to be ideal for the separation of mixtures of derivatized keto-, hydroxy-, mono- and dicarboxylic acids. The run time is less than 30 min.

Institute of Endocrinology Prague Czech Republic

References provided by Crossref.org

Myristic Acid Serum Levels and Their Significance for Diagnosis of Systemic Inflammatory Response, Sepsis, and Bacteraemia

GC/MS determination of ibotenic acid and muscimol in the urine of patients intoxicated with Amanita pantherina