HPLC analysis of emodin in serum, herbs and Chinese herbal prescriptions

Rapid and simple methods for the analysis of emodin in serum, herbs-Da Huang(大黃),Huu Jahng(虎杖),Her Shoou U(何首烏), Jyuer Ming Tzyy( 決明子)and four Chinese herbal prescriptions--Tiaowei Chengqi Tang(調胃承氣湯), Xiao Chengqi Tang(小承氣湯), Taoren Chengqi Tang (桃仁承氣湯), Da Chengqi Tang(大承氣湯) were developed by application of reversed phase HPLC system. The HPLC conditions include a RP-18 column ; elution with the mixture of MeCN and 2% HOAc; detection at 280nm and using 2-methylanthraquinone as the internal standard. We observed that the optimum elution ratio(MeCN: 2 % HOAc) and flow rates for serum samples are 73:27 and 0.9ml/min, respectively, while those for herbs and Chinese herbal preparations are 55:45 and 1.5 ml/min, respectively. The retention times of emodin/internal standard are 6.4 min/9.1 min and 8.3 min/l3.0 min, respectively, for these two elution conditions. The established HPLC methods are accurate and precise. They could be uselful in pharmacokinetic study of emodin, quality evaluation of herbs containing emodin and quality control of Chinese herbal preparations including Da Huang as their component.