Orthogonal array design as a chemometric method for the optimization of analytical procedures. Part 1. Two-level design and its application in microwave dissolution of biological samples

Abstract

The theory and methodology of two-level orthogonal array design for the optimization of analytical procedures were developed. In the theoretical part, the matrix of the two-level orthogonal array design is described while orthogonality is proved by a linear regression model. Then, the assignment of experiments in a two-level orthogonal array design and the application of the triangular table associated with the corresponding orthogonal array matrix are illustrated, followed by the data analysis strategy, in which significance of the different factor effects is quantitatively evaluated by the analysis of variance (ANOVA) technique and the percentage contribution method. Finally, a linear regression equation representing the response surface is established to estimate the factors that have a significant influence. In the application section, microwave dissolution for the determination of selenium in biological samples by hydride generation atomic absorption spectrometry as a practical example is employed to demonstrate the application of the proposed two-level orthogonal array design in analytical chemistry.