METHOD FOR DETERMINING TOXIC IMPURITIES IN GAS Russian patent published in 2000 - IPC

FIELD: analytical methods. SUBSTANCE: method includes conversion of toxic impurities being determined into condensation nuclei, mixing the latter with working fluid vapors, formation of condensation air sol and measurement of resulting air sol concentration. Conversion of toxic impurities into condensation nuclei is performed for 0.2 to 1 sec by chemical reaction or activation to form uncharged condensation nuclei or by ionization to form charged condensation nuclei (ions). As working fluids, all volatile substances can be utilized: volatile liquids, mixtures of volatile liquids or solutions of solids in volatile liquids with boiling temperatures from 170 to 300 C. Condensation nuclei thus obtained are mixed with working fluid vapors preheated to 70-150 C assuring residence time of condensation nuclei in working fluid vapors between 0.01 and 0.5 sec. Formation of condensation air sol is performed by cooling mixture for 0.2 to 1 sec to temperature 15-25 C and concentration of toxic impurities in gas is measured from concentration of formed air sol. EFFECT: increased determination sensitivity, expanded determination possibilities, and reduced power consumption.