AIMTo establish a capillary zone electrophoresis (CZE) method for determination of thymulin in human blood plasma. Thymulin is a nonapeptide produced by the thymic epithelium.

METHODSThe uncoated capillary used was 75 microns ID x 57 cm (50 cm effective length). The experimental conditions were as follows: the running buffer was phosphate-borate buffer containing 50 mmol.L-1 Na2B4O7-10 mmol.L-1 Na2HPO4 (pH 9.10); running voltage was 12 kV; operated temperature was 25 degrees C; running time was 13 minutes, detective wavelength was 200 nm.

RESULTSThe linear range of the thymulin standard curve was 1-10 micrograms.mL-1, gamma = 0.9990, the average recovery was 70.97% with RSD of 3.32%, the RSD of reproducibility was 3.05%.

CONCLUSIONThe method of CZE for determination of thymulin in human plasma is simple and reliable.