Doehlert designs with full factorials

An on-line coupling of a flow-injection system with the AAS technique was proposed. The full factorial design was used to ascertain the relevant variables which were then optimised using a Doehlert design (pH and concentration of the complexing agent)... 

Cadmium is sometimes determined together with other metals such as zinc, lead, and mercury. Generally, these applications are based on the formation of metal-ligand complexes, and some kinds of statistical or chemometric tools (full factorial designs, sequential experimental Doehlert designs, artificial neural network, partial least square) are used for distinguishing the concentrations of each analyte. In addition, some applications are based on the kinetic differentiation of the reactions related to metals and the same ligands. 

The optimisation of the parameters affecting Cd(II) adsorption by the adsorbent was performed with a 2 full factorial design. A Doehlert matrix was built to obtain an optimum set of experimental conditions from a quadratic model. 

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