欧洲药典的黄体酮含量测试方法如下: ASSAY Dissolve 25.0 mg in alcohol R and dilute to 250.0 mL with the same solvent. Dilute 5.0 mL of the solution to 50.0 mL with alcohol R. Measure the absorbance (2.2.25) at the maximum at 241 nm. Calculate the content of C21H30O2 taking the specific absorbance to be 535. 最后一句话该如何理解?百思不得其解,请各位大神指教,谢谢!