Method for Quantitative Measurement of Xanthurenic Acid in Urine

[摘要] A method is reported for determining urinary xanthenuric acid (XA), a metabolite of tryptophan. XA is extracted from urine with isobutanol (2-methyl-1-propanol), transferred to ammonium hydroxide, and separated from other urinary metabolites on thin-layer cellulose plates with use of 0.2 acetate buffer, mol/liter, pH 5.4. The XA is measured spectrophotometrically after diazotization with 2-chloro-4-nitroaniline. The method, which is specific for XA, can be used to measure amounts as low as 0.4 µg/ml of urine. It has a range from 0 to 24 µg/ml, and results within this range are reproducible within approximately ±5%. Data obtained by this procedure are comparable to results reported for other methods.

[学科分类] 过敏症与临床免疫学