A method based on capillary electrophoresis with a high frequency conductivity detection was developed for the determination of Sinomenine. The key factors for separation and determination were studied and the best analysis conditions were obtained. In the buffer of 2.0 mmol/L HAc-3.0 mmol/L NaAc-10.0% CH 3OH at a separation voltage of 22 kV, Sinomenine in the sample could be separated and detected within 4 min. The linear mass concentration of Sinomenine is in the range of 1.0—36.0 μg/mL, the limit of detection reached 0.20 μg/mL. The method was used for the analysis of Sinomenine in Sinomenium acutum and tablets satisfactorily with a recovery of 96%—102%.
A reversed capillary electrophoresis with contactless high frequency conductivity detection method to determine amino acids mixture was described. In this study,cetyltrimethylammonium bromide（CTAB） was used to reverse electro-osmotic flow in order to shorten the analysis time. β-CD was added to optimize the separation further. The effects of separation potential,concentration of CTAB,buffer electrolyte and β-CD etc. were researched and the best analysis conditions were obtained. Ten kinds of amino acids were separated and detected directly in running medium of 15.0 mmol/L diethylamine/0.10 mmol/L H3BO3/0.10 mmol/L CTAB/0.25 mmol/L β-CD（pH=11.0） at the separation potential of -20 kV within 7 min. The correlation coefficients of amino acids are 0.991—0.999 in the linear range of 1.00×10 -6 —1.00×10 -3 mol/L,the limit of detection are 0.17—0.94 μmol/L（S/N=3）. [WT5HZ]
