Factorial designs Doehlert design

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)... 

M. Zougagh, P. C. Rudner, A. Garcia-de-Torres and J. M. Cano-Pavon, Application of Doehlert matrix and factorial designs in the optimisation of experimental variables associated with the on-line preconcentration and determination of zinc by flow injection inductively coupled plasma atomic emission spectrometry, J. Anal. At. Spectrom., 15(12), 2000, 1589-1594. 

N. Jalbani, T. G. Kazi, M. K. Jamali, M. B. Arain, H. I. Afridi, S. T. Sheerazi and R. Ansari, Application of fractional factorial design and Doehlert matrix in the optimisation of experimental variables associated with the ultrasonic-assisted acid digestion of chocolate samples for aluminium determination by atomic absorption spectrometry, J. AO AC Int., 90(6), 2007, 1682-1688. 

Cu by combining full factorial and Doehlert matrix designs... 

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. 

Out of the many symmetric designs available, four are presented here that have widespread use the three-level full factorial designs, the central composite designs, the Doehlert designs and the Box Behnken designs. 

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. 

S. L. C. Ferreira, A. S. Queiroz, M. S. Fernandes and D. C. Dos-Santos, Application of factorial designs and Doehlert matrix in optimisation of experimental variables associated with the preconcentration and determination of vanadium and copper in seawater by inductively coupled plasma optical emission spectrometry, Spectrochim. Acta B, 2002, 57B(12), 1939-1950. 

K. C. Di Pietro Roux, H. F. Maltez, Sch., J. Carletto, E. Martendal and E. Carasek, Application of factorial design and Doehlert matrix for determination of trace lead in environmental samples by on-line column preconcentration FAAS using silica gel chemically modified with niobium(V) oxide. Anal. Sci., 2008, 24(3), 365-370. 

Factorial design and Doehlert designs were used to determine trace lead in environmental samples. The effect of foreign ions was evaluated using a fractionary factorial experimental design. 

Examples of spherical designs are the central composite designs (except the face-centered central composite design), the Box-Behnken, and the Doehlert design. The three-level factorial design and the face-centered central composite design are cubic designs. 

Five variables were considered in a full factorial and a Doehlert matrix design to study an online preconcentration procedure. 

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