Quantification of active ingredients in Potentilla tormentilla by Raman and infrared spectroscopy

The most important active compounds present in Potentilla tormentilla rhizomes were quantitatively determined on the basis of Raman, attenuated total reflection (ATR) and diffuse reflectance mid- and near-infrared spectra (DRIFTS) collected for the untreated plant material. Partial least-squares (PIS) models were constructed utilizing vibrational spectra and the results of reference high-performance liquid chromatography analyses. Applying Raman spectroscopy, total polyphenols, tannins, ellagitannins, procyanidins, agrimoniin, 3-O-galloylquininc acid and catechin were simultaneously quantified in tormentil rhizomes, with the relative standard errors of prediction in the 2.0-4.9% range for both calibration and validation sets. These error ranges were found to be slightly higher for infrared techniques and amounted to 2.7-6.5%.