Current aspects of qualitative and quantitative analysis of common yarrow (Achillea Millefolium L.)

Aim to develop a methodology for qualitative and quantitative analysis of flavonoids in the herb of Achillea millefolium L. 
Material and methods. The material of the study was the yarrow herb harvested in 2020 and 2021, and an industrial sample from JSC "Krasnogorskleksredstva". Additionally, we used the reference samples of flavonoids: rutin, quercetin, kaempferol, cynaroside, and luteolin, received previously during our studies of the raw materials containing the flavonoids and described using the NMR, UV and mass spectroscopy. The authenticity was determined by the thin layer chromatography (qualitative analysis). For the quantitative analysis of the total flavonoids, we used the differential spectrophotometry, conducted in accordance with Pharmacopoeial monograph 1.2.1.1.0003.15 "Spectrophotometry in ultraviolet and visible spectra". The spectral characteristics of the water-ethanolic extractions were marked using the spectrophotometer "Specord 40" (Analytik Jena AG, Germany), in cuvettes with layer thickness of 10 mm. 
Results. Based on the results of the authenticity determination, we revealed three adsorption zones with bright yellow glow in UV light at a wavelength of 365 nm (reagent AlCl3), one of which was at the level of the adsorption zone in the chromatogram of the solution of standard sample of cinaroside with a value of Rf 0.7. The dominant adsorption zone with a value of Rs 1.3 in respect to the reference sample of cynaroside was presumably attributed to cosmosiin, while the adsorption zone with a value of Rf 0.8 was detected at the level of standard sample of kaempferol. The obtained data confirmed the presence of cynaroside in the herb of common yarrow, and also the possibility to conduct the qualitative and quantitative analysis of the given raw material with the use of cynaroside as a reference sample. We developed the method of quantitative determination of the total flavonoids in yarrow herb using a reference sample of cynaroside and differential spectrophotometry at an analytical wave length of 400 nm. The content of the total flavonoids for the common yarrow herb varied from 0.410.02% to 0.740.03% (equivalent to cynaroside). The error of single determination with 95% confidence interval was 6.70%.