Liquid chromatography quantitative analysis method for 2- 2 ethyl-anthraquinone and 4 tetrahydro-2-ethyl-anthraquinone

This invention discloses a liquid chromatography quantitative analysis method for 2- ethyl-anthraquinone and 4 tetrahydro- 2-ethyl-anthraquinone. In the ShimadzuLC-20A liquid chromatograph, under the moving phase condition of Agilent ZORBAXSIL column, n-hexane- dichloromethane- ethyl acetate, and using nitrobenzene as ISTD and benzene as solution, the ratio between EAQ and H4EAQ standard substance and the ISTD is in linear relation with the concentration of standard substance within the scope of 30-140mg/L, with a linearly dependent coefficient exceeds 0.9999. This method measures the EAQ and H4EAQ content in the working solution while the time drifting is kept and the peak is changed. The standard deviation is kept within 1% and the rate of recovery is between 99.50- 101.00%. 101.00%. Comparing to reversed-phase chromatography method, the method has high degree of separation, accurate analysis results and high rate of recovery that is capable to meet the requirements of research and production.