Objective: To analyze the benzoic acid content in the Radix Paeoniae Alba treated by three kinds of process.
Methods: After harvesting, the fresh roots were processed as follows: stored in low temperature, dried after boiling a few minutes and dried immediately. Then the content of benzoic acid was determined by UV spectrophotometry.
Results: The content of benzoic acid in the above material without outer part of the cortex was at the higher level than those with outer part of the cortex. In material without outer part of the cortex, the content of benzoic acid was 0.0635% in stored sample, 0.0248% in poaching sample, 0.0639% in dried sample, 0.6635% in part of the cortex.
Conclusion: Benzoic acid was mostly distributed in the root cortex, Radix Paeoniae Alba treated by boiling can reduce the benzoic acid content. Fresh roots without cortex are comparatively economical and reasonable in distilling Paeoniflorin.