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

FIELD: analytical methods. SUBSTANCE: invention relates to methods for analyzing gases containing toxic impurities, involving absorption of the latter by sorbents, and can be, in particular, used to determine sulfur- and fluorine- containing organophosphorus impurities in gases at chemical industry enterprises and when carrying out research works. Gas to be analyzed is passed for 5-10 min at flow rate 0.3 to 5 l/min through heated to temperature from -50 to +50 C fluoroplastic powder with molecular weight 100000-140000, pore size 20 to 200 nm, and particle size 0.1 to 1.0 mm, preliminarily heat treated for 10-12 min at 330+/-3 C and sieved, to bind toxic impurities, which are then thermally desorbed for 5-8 sec at 60 to 140 C in carrying gas flow passed with flow rate from 1 ml/min to 1 l/min. Desorbed substances are further registered by known techniques. Accuracy of determination is 5•10^-7 mg/l at absolute gas humidity up to 24 mg/l, that is at concentration of water vapors by 4,8•10⁷ times superior to concentration of measured impurities. EFFECT: increased accuracy of analysis.