FIELD: chemistry.
SUBSTANCE: device comprises a concentrator 1, immersed in a Dewar vessel 5 containing liquid nitrogen 8. The concentrator 1 is formed as a tube with the crane 2, with the inlet 3 for air intake, with the container 6 for liquid air condensation, with water condensate receiver 7, with the insulating gasket 4. Wherein the concentrator 1 is installed in the Dewar vessel 5 through an opening in the insulating gasket 4 so that the tank 6 for liquid air condensation is immersed in liquid nitrogen 8. Obtaining water condensate from the air is carried out by means of the installation. The water condensate is obtained from the air via the air intake and its condensation under cooling with liquid nitrogen. The liquid air is vapourised until the frozen water condensate is obtained. Melting frozen water condensate is carried out. An extractant in a dispersant is introduced into the water condensate, and the microextraction of impurities from the water condensate is performed. The extract emulsion formed in the water condensate is separated by its centrifugation to obtain an extract phase. The factor Fextr of the impurity concentration from the water condensate to the extract and the integral factor Fint of the concentration of impurities from the air in the extract are determined. The extract phases are sampled, and the obtained extract is analyzed. The factor Fextr of the impurities concentration from the water condensate into the extract is obtained according to the formula: Fextr=1/(D-1+Ve/Vwat, where D is the impurities distribution coefficient in the water-extractant system, Ve - the volume of the extractant phase, Vwat - the amount of water condensate. The calculation of the integral factor Fint of the impurities concentration from the air into the extract is carried by the formula: Fint=Fwcond⋅Fextr, where Fint is the integral factor of the impurities concentration from air to the extract, Fwcond - the factor of concentration from the air into the water condensate, Fextr - the factor of impurities concentration from the water condensate to the extract. The necessary amount of liquid air V lair to obtain the necessary amount of the water condensate is pre-determined according to the formula: Vlair= (Vwat⋅ρwat) / (F⋅ρlair), where V lair is the volume of liquid air; Vwat is the amount of water condensate, necessary for performing the extraction / microextraction; ρwat - the water density at the extraction temperature; F - the content of atmospheric moisture (in weight units) per unit weight of the sampled air; ρlair is the liquid air density at the temperature of performing the air condensation. Obtaining liquid air by condensing it in a container for liquid air condensation, the evapouration of the condensed liquid air in the liquid air condensation tank, and the extraction of the water condensate from the water condensate receiver are performed additionally. The concentrations of substances detected in the air are calculated by the formula: Cair=Cextr/Fint, Cair is the concentration of the analyte in the sample air (wt %), Cextr - concentration of the analyte in the extract (wt %), Fint - the integral factor of the impurities concentration from the air into the extract.
EFFECT: increased sensitivity of the analysis, reducing the limits of the impurities detection in the air.
10 cl, 3 dwg, 1 tbl
