RANDOM-WALK SIMULATION OF FLOW-INJECTION ANALYSIS - EVALUATION OF DISPERSION PROFILES

The use of the random walk model for simulating peak shapes in flow in jection analysis (FIA) is investigated. Studies are limited to the cas e of dispersion in straight tubes with laminar flow (no reaction), but more precise peak shape data than has previously been available is pr ovided. Peak shapes obtained with the random walk model are compared w ith experimental results and predictions made by other theoretical app roaches. Comparisons utilize a wide variety of conditions, including t hose treated by other authors. Favourable agreement is obtained in all cases, although some differences with experimental results are observ ed. The computational aspects of the random walk algorithm are conside red and guidelines for its implementation are provided. The versatilit y of the algorithm is demonstrated through the presentation of simulat ion results for modified laminar flow profiles, asymmetric flow profil es, and conditions of infinite radial diffusion.