| Summary: | 碩士 === 國立交通大學 === 應用化學系所 === 97 === The temporal signals of well diffusive solutes (typical small molecules) monitored using conventional single-channel detectors are usually Gaussian-like profiles with apparent tailing in flow injection analysis (FIA). According to the previous researches in our laboratory, the spatial signals monitored using the multi-channel detector were nearly Gaussian and symmetric under typical FIA conditions. The shape difference between the temporal and spatial profiles appeared due to the way how the measurements were conducted. The difference thus occurs is called spatial-temporal difference.
It has been reported that the temporal signals of nanoparticles in FIA emerged usually as double-humped shapes, including so-called convection and diffusion peaks. In this study, we examined how the difference between the temporal and spatial profiles of tartrazine and Ag nanoparticles could come out using the laboratory-made multi-channel detector. The results showed a considerable difference between the temporal and spatial profiles for both solutes. However, their relative standard deviations, the parameter to describe the solute dispersion behaviors, turned out to be quite similar. The solute profile, acquired using the single-channel detection, was found to show somewhat double-hump character for Ag nanoparticles when the RSD was nearly 19.57%. However, the corresponding spatial signal of the same sample remained Gaussian with the RSD of 22.25%. In addition, the spatial-temporal difference became greater as the dispersion (RSD) of the temporal profile became larger. The dispersion was thus proved one of the major factors to affect the spatial-temporal difference. According to the results obtained using multi-channel detection, we also derived the relation between the signal RSD and other experimental factors including the molecular diffusion coefficient, and the tube length.
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