Capillary Electrophoresis for Detection of Inherited Disorders of Purine and Pyrimidine Metabolism

Abstract

Measurement of purine and pyrimidine metabolites presents complex problems for separations currently performed by HPLC and thin-layer chromatography in clinical practice. We developed a novel capillary electrophoresis method for this purpose. Separations were performed in 60 mmol/L borate-2-amino-2-methyl-1-propanol-80 mmol/L sodium dodecyl sulfate (pH 9.6) at 35 degrees C. The conditions reported allowed separation of all diagnostic metabolites from major urinary constituents in an analysis time of 3 min and with a separation efficiency of 220 000 theoretical plates/m. The clinically important metabolites were detectable at concentrations of 0.85-4.28 micromol/L. The method was linear over the range 5-500 micromol/L (r >0.99). The within-run and intra- and interday imprecision (CV) was <5%. Characteristic abnormalities were detected in the electropherograms of urine samples from patients with purine and pyrimidine enzyme deficiencies. We provide the electrophoretic and spectral characteristics of many intermediates in purine and pyrimidine metabolism and describe common artifacts from medication and ultraviolet-absorbing compounds. Capillary electrophoresis is a valuable screening tool in the detection of inborn errors of purine and pyrimidine metabolism.