Gas Diffusion in pFI Format
Following the downscaling guidelines outlined in the previous sections, the volume of the channel between injector and detector was minimized by keeping the mixing coil short and by reducing the length of the diffuser to only 2 cm (volume 40 microliters on donor and 40 microliters on acceptor side). Miniaturization makes the diffuser much easier to assemble, and facilitates accumulation of volatile species in a small volume of the acceptor stream, while a large volume of the donor stream is slowly passing trough the diffusion unit. The signal is further amplified by using 10 cm long light path Garth’s flow cell for spectrophotometric detection. The efficiency of this approach is documented in next sections describing assay of ammonia and total inorganic carbon.
1.2.35.
