Optimization by means of responses surface of an analytical sequence using a sequential injection system.

An experimental design method was applied to determine the optimum working conditions for sequential injection analysis (SIA) to obtain second-order data that will be treated using multivariate curve resolution with alternating least squares (MCR-ALS). The critical step is to design an analytical sequence that provides relevant information. This sequence depends on parameters related to the system, the chemical reaction, and the chemometric treatment of the data. Also, from the multiple responses that quantify the quality of this analytical sequence, a single response is determined from the desirability function. This method involves a factor-screening step, in which both the global desirability function and the individual responses are considered and a response surface-modelling step, in which the most relevant factors are considered.