Перегляд за Автор "Dekusha, Hanna"

Зараз показуємо 1 - 1 з 1

Аpplication of an improved technique for measuring the mass fraction of alcohol-containing raw materials in cosmetic products
(2023) Levchuk, Iryna; Shemanska, Yevheniia; Dekusha, Hanna
An improved technique for measuring the mass fraction of ethyl alcohol in water-alcohol solutions using gas-liquid chromatography with a vapour-phase sampler has been proposed. The principle of the method consists in the transfer of volatile components, including ethyl alcohol, from the solution to the vapor phase, its introduction into the chromatograph, the separation of the mixture on a capillary column, followed by the registration of the signal on the flame ionization detector. The prepared sample, the working solutions of the mixtures and the mixture for checking the retention time are heated in a stoppered vial. This allows you to balance the content of volatile components present in the liquid and in the vapor phase. Part of the equilibrium sample of the steam is introduced into the gas chromatograph column. The static vapor phase sampler provides the possibility of introducing 3 ml of the vapor phase (volatile substances) of the sample directly to the analytical column, increasing the sensitivity of the technique and extending the resolution of the column. The mass fraction of ethyl alcohol is calculated by the external standard method according to the ratio of the areas of the chromatographic peaks of ethyl alcohol from the mass fraction of ethyl alcohol in solution. This technique makes it possible to test cosmetic products for the content of ethyl alcohol in water-alcohol and gel solutions, as well as to confirm the quality and safety of alcohol-containing raw materials in accordance with the requirements of the Technical Regulations for cosmetic products.