On the possibility to improve the performance of flow injection analysis by deconvolution of spectrophotometric data

The concentration profile of chemical species pumped through a tubular system of 0.5 mm inner diameter is found to be trapezial shaped, as described theoretically by including the spatial resolution of the instrument, friction and diffusion. By applying the theory, which is based on the concept of segment flow, to experiments, it is shown that an injected segment of solute is diluted predominantly at the front and at the tail proportion of the segment in motion. A double-peaked structure in experiments of Flow-Injection Analysis (FIA) was identified and by including all the data of the experimentally measured responses it was possible to obtain an improvement of the sensitivity by a factor of 22 and obtain almost a factor of three improvement on the standard deviation.