A gas chromatographic/electron impact mass spectrometric method for the isolation and derivatization of plasma taurine for use in stable isotope tracer kinetic studies

Abstract

AbstractTo aid in the understanding of the human requirement for 2‐aminoethanesulphonic acid (taurine), a method was developed for the analysis of plasma taurine and used for preliminary studies of the kinetics of plasma taurine in three healthy adult volunteers. A gas chromatographic/electron impact mass spectrometric (GC/EIMS) stable isotope ratio method was developed for the measurement of enrichment of the tracer [1,2‐13C2] taurine in plasma. Natural abundance taurine and [1,2‐13C2] taurine were analysed as their N‐pentafluorobenzoyldi‐n‐butylamide (PFB‐dBA) derivatives by GC/EIMS. With the addition of an internal standard, methyltaurine, the taurine concentration could also be measured. After an overnight fast, three healthy adult human subjects were given an intravenous priming dose of [1,2‐13C2] taurine (3 μmol kg−1), which was immediately followed by a continuous infusion of the tracer (3 μmol kg−1 h−1) for 6 h. The mean plasma plateau enrichment was 8.07 ± 0.46 mol% excess (RSD = 5.67%) and a rate of appearance of 34 ± 2.23 μmol kg−1 h−1 was calculated. The plasma taurine concentration was found to be 56 ± 14 μmol l−1. This technique for the assessment of plasma taurine kinetics should enhance the understanding of taurine metabolism as it could be a conditionally essential amino acid in man.