Simplified two-step column-chromatographic determination of taurine in urine

Abstract

A two-step column-chromatographic procedure for accurate and rapid determination of taurine in urine is described. Sulfosalicyclic-acid deproteinized samples are chromatographed on a 0.9x10 cm column of cation-exchange resin (AG 50W-X8), with use of a pH 2.2 sodium citrate eluting buffer such that taurine and the more highly acidic compounds in urine are eluted in the void volume, and then on a 0.9x8 cm column of anion-exchange resin (AG 2-X8), from which taurine is preferentially eluted with 1 mol/liter acetic acid. The color developed with ninhydrin is directly proportional to taurine amounts as low as 0.01 μmol/sample. The method is highly reproducible, with analytical recoveries > 95%. The presence of 333 μmol of urea and 1 μmol of cysteic acid did not interfere in the analysis. When a mixture of C 14 -labeled amino acids other than taurine were co-chromatographed with taurine, less than 2% of the total counts loaded were located in the taurine fraction. Values for urinary taurine excretion by rats according to the present method agreed well with values obtained with an automated amino acid analyzer. Advantages of the present method for the determination of taurine are discussed.