Separation of derivatized aliphatic aldehydes in beverage by nonaqueous capillary electrophoresis

A simple and mild method for the separation of aliphatic aldehydes based on a condensation reaction with 9,10-phenanthrenequinone as labeling reagent with nonaqueous capillary electrophoresis has been developed. The detection was performed with a diode array detector (DAD). A 58. 5 cm (50 cm effective length) x 50 mu m i. d. untreated fused-silica capillary was used. To optimize the conditions, the background electrolyte concentration, column temperature, voltage and other factors were evaluated. The results indicated that the buffer concentration had a great impact on the separation, but the influences of temperature and added additives on the resolution were not obvious. The optimized conditions were as follows : 80 mmol/L ammonium acetate, 1. 4 mol/L acetic acid, voltage of 28 kV, column temperature of 20 degrees C and DAD detection at 254 nm. The samples were introduced atmospherically with the injection at 5 kPa (50 mbar) for 8 s. The results indicate that, seven aliphatic aldehyde derivatives and actual samples can be achieved baseline resolution under the proposed conditions.