“…In many cases, this method approaches to the goal of maximizing the response but without achieving the optimum value . One of the reasons of the unsuccessful results is that this method does not take into account the interactions between variables. , Furthermore, this method demands a great number of experiments time-consuming process. Some other chemometrics methods can be used for this purpose, and SIMPLEX, for instance, has been previously applied in a successful manner. − The work of Parker et al deserves special mention; the authors checked four methods, factorial design, regression and canonical analysis, and SIMPLEX, to optimize the determination of As and Se through HG-ICP-AES …”