A high-performance liquid chromatographic method for determination of hypoxanthine in cord plasma

A reversed-phase high-performance liquid chromatographic method was developed for the analysis of hypoxanthine in cord plasma. Cord plasma was precipitated with ammonium sulphate and after centrifugation the supernatant was injected into the chromatographic system. Separation of hypoxanthine was optimal with phosphate buffer (20 mmol/l, pH 7.65-7.75) as the mobile phase. Limit of determination using 200μl of the sample was found to be 1 μmol/l with a coefficient of variation of <10%. The imprecision of this method at the 10 μmol/l level was about 2%. The method described in this report for determination of hypoxanthine in cord plasma would also be suitable for determination of hypoxanthine in other biological fluids in clinical investigations. We have also determined reference values for hypoxanthine in citrate-preserved cord plasma. Rigorous sampling conditions and sample handling are important to achieve accurate results.