Determination of diosgenin and ruscogenin in Radix Ophiopogonis by nonaqueous capillary electrophoresis / 药学学报

Nonaqueous capillary electrophoresis is used for the determination of the contents of diosgenin and ruscogenin in Radix Ophiopogonis. The operating buffer was composed of 20 mmol x L(-1) Na2B4O7-HCl (pH 7.61) in 70% methanol. The applied voltage was 25 kV and detection potential was at +0.70 V. With these conditions, the components were successfully separated. The content of diosgenin in Radix Ophiopogonis was 0.018 mg x g(-1) and ruscogenin was 0.008 mg x g(-1). The average recoveries of diosgenin and ruscogenin were 102% and 99.2%, respectively. A new method of the quality control of diosgenin and ruscogenin in Radix Ophiopogonis is provided.

Separation of salicylic acid drugs by aqueous and nonaqueous capillary electrophoresis with conductance detector / 药学学报

<p><b>AIM</b>To develop a method for separating salicylic acid drugs by aqueous and nonaqueous capillary electrophoresis with conductance detector.</p><p><b>METHODS</b>Fused-silica capillary (55 cm x 50 microns ID) was used. The effects of concentration and pH of the running buffer, running voltage and injection time were studied. Salicylic acid (SA), acetylsalicylic acid (ASA) and sulfosalicylic acid (SSA) can be separated in a 10 mmol.L-1 Tris-30 mmol.L-1 H3BO3 buffer (pH 8.0), the separation voltage and injection time were 24 kV and 10 s, respectively. But tailing peaks appeared. In order to improve the separation efficiency and the sensitivity, ethanol was used as nonaqueous solvent.</p><p><b>RESULTS</b>High sensitivity and resolution for SA, ASA and SSA were obtained in ethanol media, and there was excellent linearity between peak area and concentration of the analytes in the concentration range of 0.05-100 mg.L-1, 5.0-250 mg.L-1 and 0.08-100 mg.L-1 for SA, ASA and SSA, respectively. All the correlation coefficients were over 0.995.</p><p><b>CONCLUSION</b>The analysis of SA and ASA in aspirin tablets was tried and good results were obtained in ethanol media. There was higher sensitivity and separation efficiency than in aqueous media.</p>