COMPARISON OF THE POWELL AND SIMPLEX METHODS IN THE OPTIMIZATION OF FLOW-INJECTION SYSTEMS - SIMULATION ON MODELED EXPERIMENTAL SURFACES AND EXPERIMENTAL OPTIMIZATIONS

The Powell algorithm is adapted for the optimization of a flow-injection system for the spectrophotometric determination of ammonia based on the indophenol blue reaction. Its performance is compared with that of the modified simplex method in experimental optimization, and in simulation of the course along the experimental response surface, which can be modelled conveniently for this analytical system. The Powell algorithm needed fewer evaluations of the objective function (maximal sensitivity and sample throughput), thus minimizing experimental work, particularly in the initial optimization.