Taking samples esp. for waste gas contg. moderately or difficulty volatile cpds. - esp. poly-chloro-dibenzo(p) di:oxine(s) and poly-chloro-benzofuran(s) by sepg. partial stream, passing through dust filter and adsorbent resin and analysing adsorbed material

摘要

Taking samples, esp. of waste gases, contg. moderated or difficultly volatile substances in a gaseous or aerosol phase, involves (a) withdrawing a partial stream, cooling and filtering if necessary, and leading into a sepn. zone in which the substances to be investigated are sepd. and fixed as dust or in the condensate, and (b) after taking of samples is finished, extracting the sepd. substances and passing to an analyser. The novelty is that in analysing organic substances, esp. polychlorinated dibenzo(p)dioxines (PCDD) and polychlorinated dibenzofurans (PCDF), samples of the partial streams are subjected to only a 2-stage sepn., i.e. (c) passage through an inert dust filter, (d) passage through a zone charged with an adsorber (e.g. a synthetic resin adsorber with multi-reticular structure), without previous removal of gaseous water in the waste gas, and (e) finally analysis of organic substances adsorbed in the dust filter and the adsorbent. USE/ADVANTAGE - Appln. is esp. to analysis of waste gas from furnaces, esp. determn. of polychloro-benzene, polychloro-phenols, polychloro-biphenyls, PCDD, PCDF, polybromo- dibenzo(p)dioxines, polybromo-dibenzofurans, polybromo- and polychloro-dibenzo(p)dioxines and -dibenzofurans, and polycyclic aromatic hydrocarbons. The process is independent of the temp. of the waste gas (0-1000 deg.C), the water content (up to above 300 g/cubic m), and the dust content (up to above 1 g/cubic m), and may be continuous or carried on for long periods. The appts. is simple and avoids sec. contamination. The probe and the cartridge contg. dust filter and adsorbent can be replaced in a few mins., and tedious cleaning of the appts. is avoided.