Capillary electrophoresis for detection of inherited disorders of purine and pyrimidine metabolism

Background: Measurement of purine and pyrimidine metabolites presents compl ex problems for separations currently performed by HPLC and thin-layer chro matography in clinical practice. We developed a novel capillary electrophor esis method for this purpose. Methods: 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. Results: The conditions reported allowed separation of all diagnostic metab olites from major urinary constituents in an analysis time of 3 min and wit h a separation efficiency of 220 000 theoretical plates/m. The clinically i mportant metabolites were detectable at concentrations of 0.85-4.28 mu mol/ L. The method was linear over the range 5-500 mu mol/L (r >0.99). The withi n-run and intra- and interday imprecision (CV) was <5%. Characteristic abno rmalities were detected in the electropherograms of urine samples from pati ents with purine and pyrimidine enzyme deficiencies. We provide the electro phoretic and spectral characteristics of many intermediates in purine and p yrimidine metabolism and describe common artifacts from medication and ultr aviolet-absorbing compounds. Conclusion: Capillary electrophoresis is a valuable screening tool in the d etection of inborn errors of purine and pyrimidine metabolism. (C) 1999 Ame rican Association for Clinical Chemistry.