3.4. Sample AnalysisThe established

3.4. Sample Analysis
The established analytical method was applied for the quantitative analysis of two active components, 4 and 7, in three different batches of the aerial part of P. nodifloracollected at the same location in different years and seasons (Figure 4). Each sample was analyzed in triplicate to determine the mean content, and the peaks in chromatograms were identified by comparing the retention times and the online UV spectra with those of the standards. The contents of compounds 4 and 7 were 0.048 and 0.072 mg/g in 2007-02-PNM, 0.296 and 0.474 mg/g in 2009-06-PNM, and 0.545 and 0.381 mg/g in 2010-06-PNM, respectively. The quantitative analysis results showed that the crude extract of PNM, even in the different seasons (spring and summer), generally contained the two selected active constituents. From the results obtained, the contents of active compounds were higher in the summer than in the spring. It is known that the different growing place, climate, and harvest processing may affect the level of these compounds. Although PNM in the autumn and in the winter was not collected and detected, the results showed PNM in blossom season (May to August, summer), yielding more active compounds, might serve the good quality and quantity of PNM when used as a cosmetic or herbal medicine additive.