| 摘要 |
<p>Apparatus for removing amine compounds from an air sample containing oxides of nitrogen without loss due to formation of nitrosamine artefacts comprises a cartridge (20) having an interior separation zone (A) between a first port (22) and a second port (24) at opposite ends of the cartridge. The separation zone (A) contains an air pervious packing (28) of a granular, solid phase amine complexing agent. The apparatus is used by first driving an air sample through the separation zone (A), and subsequently backflushing the zone with an eluent. To extract the amine compounds trapped by the packing (28) in the first step, the eluent is a solvent for the amine complexing agent in the separation zone (A). If desired, the amine compound concentration of the eluate which leaves the cartridge through the first port (22) can be determined using known techniques, to give an indication of the amine concentration in the original sample. <IMAGE></p> |
