Determination of ergot alkaloids in plasma by high-performance liquid chromatography and fluorescence detection.

Liquid chromatographic methods for the determination of ergotamine and methylergometrine in plasma have been developed. The samples are extracted with an organic solvent at pH 9.0 cleaned by extractions and finally injected on an ODS-Hypersil reversed-phase column with acetonitrile-ammonium carbonate buffer as the mobile phase. THe polarity of solvents used for extraction and the mobile phase are varied with the compounds of interest. Ergocristine is used as internal standard for ergotamine, and methysergide for the determination of methylergometrine. The stability of samples and standard solutions for calibration are discussed. Conditions for high selectivity and sensitivity of detection are given. Concentrations down to 100 pg/ml of plasma can be detected with a 3-ml sample.