| 摘要 |
A method and apparatus are disclosed for extracting N-nitroso compounds from air samples without artifact formation of nitrosamines from precursors in the sample. The apparatus includes a cartridge having two zones between a first port and a second port. The first zone, closest to the first port, contains an air pervious packing of a granular, solid phase amine complexing agent. The second zone, closest to the second port, contains an air pervious packing of a mixture of a granular, solid phase amine complexing agent and a particulate sorbent adapted to extract and concentrate N-nitroso compounds from air. The method includes a first step of driving an air sample through the first and second contiguous zones of the cartridge in succession, and a second step of driving an eluent through the second and first zones in succession, or backflushing the cartridge. To extract N-nitroso compounds, the eluent is a polar, or nitrogenous based, solvent for both N-nitroso compounds and the amine complexing agent in the second zone of the cartridge. The method may contain the further step of determining the N-nitroso compound concentration of at least a portion of the eluate which passes from the first zone following the second step of the method. |
