[Determination of formic acid in urine by high performance capillary zone electrophoresis]

The amounts of formic acid in human urine has a direct bearing on the people's health. In this paper, high performance capillary zone electrophoresis was applied to separate formic acid of urine with a buffer system of 5 mmol/L phthalate-0.5 mmol/L hexadecyltrimethyl ammonium bromide (CTAB) and pH 6. Separations were performed in a 50 cm x 50 microns i.d. fused silica capillary (effective length 48.5 cm) at 25 degrees C. A negative potential of 30 kV was used for each experiment. Sample was introduced into the capillary by pressure at kPa for 10 s. Indirect UV detection was operated at 210 nm and reference wavelength at 380 nm for all experiments. Capillary was rinsed for 5 min with 0.1 mol/L sodium hydroxide and buffer solution before each run. Urine was injected directly after filtered through 0.45 micron membrane. The results are satisfactory.