Guard column hardware kit

The object of the study is the leaves of the plants of B. prostrata in the flowering phase collected in the period 2019-2020 in Novosibirskaja Oblast', the Republics of Khakassia, Buryatia, Altai, Tyva, etc. (Table 1). The raw materials were dried in well-ventilated rooms, crushed to a particle size of 2 mm, mixed and an average sample was taken.
Double extraction with 70% ethanol in a water bath (60-70°C for 1.0-1.5 h.) was carried out to extract the phenolic compounds. An exact weight (0.1 g) of the crushed material was extracted with 30 ml of aqueous ethanol for 30 min followed by 20 ml for 20 min. The residue on the filter was washed with 5 ml of 70% ethanol. The combined extract was concentrated to 10-15 ml (exact volume). To free from impurities, 1 ml of the extract was diluted with bidistilled water to 5 ml and passed through a Diapack C16 cartridge.
The component composition of the phenolic complex of the samples was studied by high-performance liquid chromatography on an analytical HPLC system consisting of an Agilent 1200 liquid chromatograph. The chromatographic separation was conducted at 25°C on a Zorbax SB-C18 Column (4.6 × 150 mm, 5 µm internal diameter) with the Agilent Guard Column Hardware Kit. Detection was performed at a wavelength of λ = 360 nm [11] . Quantification of individual components in plant samples was carried out using the external standard method.