A rapid capillary electrophoresis with electrochemiluminescence method for the assay of human urinary proline and hydroxyproline.

A novel simultaneous determination method for free and total proline (Pro) and hydroxyproline (Hyp) in human urine was developed, based on capillary electrophoresis (CE) with electrochemiluminescence (ECL) detection, using tris-(2,2'-bipyridyl) ruthenium(II). Experimental conditions, such as the Ru(bpy)(3)2+ concentration, detection potentials, buffer concentration and pH in CE or in the ECL cell, injection voltage and time were investigated in detail. Under optimized conditions, the linear range, detection limit and sample recoveries for the method were 0.01-2 mmol/L (correlation coefficient, 0.9970), 4 micromol/L and 96.4-101.2% in human urine, respectively. The results show that the method has potential applications in monitoring the level of Pro and Hyp in body fluids from patients with bone disease, tumours or chronic uraemia.