The behavior of seven hydroxy anthraquinone derivatives was studied by capillary zone electrophoresis and micellar electrokinetic chromatography. The effects of buffer pH (6.5 - 10.8) and sodium dodecyl sulfate concentration (10 - 20 mmol L-1) on the effective mobilities of the analytes and their separation were tested.
A comparison of the two optimized separation systems showed that micellar electrokinetic chromatography was superior as it permits separation of all the seven analytes within 15 mins., using 15 mmol L-1 sodium dodecyl sulfate in 10 mmol L-1 tetraborate buffer, pH 8.5, at a voltage of 20 kV. The calibration curves were linear in the concentration range from 5.0.10-7 to 5.0.10-4 mol L-1 for most of the analytes, at a detection wavelength of 254 nm.
LOD and LOQ values of the analytes were in the ranges of 2.10.10-7 - 1.28.10-6 mol L-1 and 6.99.10-7 - 4.25.10-6 mol L-1, respectively.