Repeatability of this method was as

Repeatability of this method was assessed by analyzing five independently prepared samples (2010-06-PNM). R. S. D. values of content and retention time of compounds 4 and 7were all less than 2.2%, which indicated good repeatability.
The recovery test was evaluated by standard addition method. Onopordin (4, 0.20 mg/g) and eupafolin (7, 0.15 mg/g) were spiked into the sample (2010-06-PNM) and then extracted and analyzed using the proposed procedure. As shown in Table 5, the recoveries of compounds 4 and 7were in the range of 93.50–97.33% with an R. S. D. value less than 2.40%. Therefore, this HPLC-UV method was considered precise, accurate, and sensitive enough for the quantitative evaluation of active compounds 4 and 7 in P. nodiflora.