Abstract: A new method for analyzing diuretics by capillary electrochromatography using poly(1-hexadecene-co-TMPTMA) monolithic column was established. Experimental conditions including the mobile phase, separation voltage, and injection condition were optimized for the analysis. Under optimized experimental conditions, six diuretics were separated within 11.0 min with the limits of detection （LODs） (S/N=3) in the range of 0.35－0.65 μg/mL. The method showed good linearity (R2≥0.9908) in the range 1.15 and 86.0 μg/mL. The recoveries obtained from the analysis of spiked urine sample were between 81.9% and 105% with the relative standard deviations (RSDs) lower than 4.7%. It can be concluded that this new method possessed good repeatability and stability in analyzing diuretics, and was successfully applied to the analysis of real urine samples from volunteers. Therefore, this method could be applied to scanning diuretics in human urine samples.

Key words: chromatographic separation, diuretics , monolithic column, preparation, capillary electrochromatography (CEC)