HPLC determination of D-glucaric acid in human urine.

An isocratic HPLC method has been developed for the direct measurement of D-glucaric acid in human urine. Pretreatment of urine with a boronic acid gel removed many interfering substances, including L-ascorbic acid and D-glucuronic acid. This method has a detection limit of 10 microM D-glucaric acid (approximately 7 mumoles/g creatinine). The run-to-run precisions were 9.1% and 7.7% at urinary D-glucaric acid concentrations of 41 and 219 mumoles/g creatinine, respectively. Urinary D-glucaric acid concentrations in normal adults were found to cover a range of 15 to 89 mumoles/g creatinine (mean = 47 mumoles/g creatinine). The sensitivity of this method in detecting abnormal elevations in D-glucaric acid was demonstrated through its ability to measure changes in urinary concentrations with time after ingestion of D-glucuronolactone.