Sensitive gas chromatographic–high resolution mass spectrometric method for the determination of methylmalonic acid in bovine plasma
A sensitive and highly specific method for the determination of methylmalonic acid (MMA) in bovine plasma is described. Following solvent extraction and butylation, samples are analysed by gas chromatography and detected using high-resolution mass spectrometry. The limit of detection for the assay was 0.025 µmol l–1 MMA and the recovery of added MMA ranged from 98 to 103%. The application of the method is demonstrated for the analysis of MMA in plasma taken from cattle that had been maintained on a cobalt-deficient diet for 64 weeks.