Influence of different compatibility on contents of calcium and magnesium dissolution in maxing shigan decoction / 中国中药杂志

<p><b>OBJECTIVE</b>To establish a method for the determination of gypsum and magnesium in decoction by capillary zone electrophoresis and study the influence of different compatibility on the contents of calcium and magnesium dissolution.</p><p><b>METHOD</b>Nine decoctions with gypsum were prepared and analysed by L9 (3(4)) orthogonal design and the contents of calcium and magnesium ions were determined by the set method. The conditions of the experiment were a running buffer of 6.4 mmol x L(-1) imidazole solution (glacial acetic acid ajusted pH to 3.50) and an applied voltage of 10 kV (room temperature). Samples were introduced by hydrodynamic injection (8 cm x 7 s) and determined with on-column UV monitoring at 214 nm. Copper sulphate was chosen as the internal standard.</p><p><b>RESULTS</b>The linear responses covered the range from 0.009 68 mg x L(-1) to 9.68 mg x L(-1) (r = 0.998 1) for calcium, the detection limits (S/N = 3) and the quantitation limits (S/N = 10) of calcium were shown to be 0.002 1 mg x L(-1) and 0.007 1 mg x L(-1), respectively. The average recovery for calcium was 100.4%. The linear response covered the range from 0.01 mg x L(-1) to 10 mg x L(-1) (r = 0.995 9) for magnesium. The detection limits (S/N = 3) and the quantitation limits (S/N = 10) of magnesium showed to be 0.002 8 mg x L(-1) and 0.008 9 mg x L(-1), respectively. The average recovery for magnesium was 96.4%.</p><p><b>CONCLUSION</b>The method is simple, rapid, cost-effective and precise with satisfactory results. The influence of Ephedra and Semen Armeniacae Amarum on the contents of gypsum dissolution are significant, while that of Radix Glycyrrhizae on the contents of gypsum dissolution is insignificant. The influence of Ephedra on the contents of magnesium dissolution are significant, while that of Semen Armeniacae Amarum and Radix Glycyrrhizae on the contents of magnesium dissolution are insignificant.</p>

Determination of cytidine and adenosine in cordyceps by monolithiccapillary electrochromatography / 中国中药杂志

<p><b>OBJECTIVE</b>To develop a capillary electrochromatography method for determination of cytidine and adenosine in cordyceps with monolithic column.</p><p><b>METHOD</b>The total length of the home-made ploy-butyl methacrylate (PBMA) monolithic capillary electrochromatographic column was 34.5 cm with the effective length of 26.0 cm. The mobile phase was 20 mmol x L(-1) borax solution (adjusted pH to 3.5 using acetic acid); the operation voltage was 15 kV; sample injection pressure was 6 bar x 0.1 min; column temperature was 30 degrees C and the detection wavelength was set at 214 nm. The internal standard solution was 100 mg x L(-1) trimethoprim solution [ethanol-mobile phase (1 : 1) was used as the solvent].</p><p><b>RESULT</b>The results indicated that the concentrations of cytidine and adenosine within the range of 12.5-125 mg x L(-1) were linearly correlated with the relative peak areas, and the correlative coefficients (r) were 0.999 8 and 0.999 3, respectively. The LOD (S/N = 3) and LOQ (S/N = 10) of cytidine were 2.14 and 7.14 mg x L(-1), and those of adenosine were 1.88 and 6.25 mg x L(-1). The average recoveries of the two nucleosides were from 97.2% to 103.5% with relative standard deviation (RSD) within 0.9%-2.6% in three levels.</p><p><b>CONCLUSION</b>The method is effective and credible. It can be used to determine the contents of cytidine and adenosine in cordyceps.</p>

Determination of ephedrine and pseudoephedrine in Herba Ephedrae and Maxing Shigan Tang by capillary zone electrophoresis / 中国中药杂志

<p><b>OBJECTIVE</b>To establish a method for the determination of ephedrine and pseudoephedrine in Herba Ephedrae and Maxing Shigan Tang by capillary zone electrophoresis.</p><p><b>METHOD</b>The conditions of the experiment were optimized with a fused-silica capillary of 60 cm x 50 microm (50 cm effective length) in a running buffer of 50 mmol x L(-1) borax-20 mmol x L(-1) threonine (pH 9.27) and an applied voltage of 15 kV (room temperature). Samples were introduced by hydrodynamic injections (10 cm x 20 s)and determined with on-column UV monitoring at 210 nm. Phenobarbital was chosen as the internal standard.</p><p><b>RESULT</b>Ephedrine and pseudoephedrine are separated successfully within 8 min. The linear responses covered the ranges from 21.3 to 213 mg x L(-1) (r = 0.9996) for ephedrine and from 8.4 to 84 mg x L(-1) (r = 0.9995) for pseudoephedrine. The detection limits (S/N = 3) of ephedrine and pseudoephedrine were shown to be 1.45 and 1.48 microg x mL(-1), respectively, The quantitation limits (S/N = 10) of ephedrine and pseudoephedrine were shown to be 4.81 and 4.93 mg x L(-1), respectively. The average recoveries for ephedrine and pseudoephedrine were 97.5% and 98.6% with RSD less than 5.0%.</p><p><b>CONCLUSION</b>The method is simple, rapid, cost-effective and precise with satisfactory results.</p>