The regularities of volatile organic compounds standard gas mixtures generation based on the chromatomembrane gas extraction of these compounds from the flow of an aqueous solution with a given concentration into the extractant gas stream were considered. It was shown that the chromatomembrane gas extraction allowed the generation of water-saturated standard gas mixtures with the predetermined concentrations of volatile organic compounds at the ppm level. The preparation of these gas mixtures is relevant for the analysis's metrological assurance of the moist atmospheric air and exhaled air for the purpose of non-invasive diagnostics. The metrological possibilities of chromatomembrane generation of the standard gas mixtures in the mode of complete extraction of the target components from the solution flow into the gasextractant stream and in the mode of equilibrium saturation of the gas-extractant stream were discussed. The choice of modes depended on the distribution coefficients (K) of the target components between the water and gas phases. For the polar compounds with K > 100 (alcohols, ketones) the equilibrium saturation mode was preferable, and for the chlorinated hydrocarbons (K < 20) the full extraction mode was recommended. The relative error calculated for the two modes did not exceed 7%. The volume of the generated standard gas mixtures with the constant concentration of the target components for 1 liter of the generating solution was from 10 liters to 1000 liters, depending on the distribution coefficients of these components. Compared with the traditional continuous gas extraction from the stationary aqueous solutions, its chromatomembrane variant allowed for a 5 to 20-fold increase in the volume of the generated gas mixture without refilling.