title: Application of ridge trace analysis in direct spectrophotometric calibration.
abstract: The use of ridge trace analysis for multivariate calibration problems is described. Application is made to the simultaneous quantitative determination of components for several pharmaceutical systems with unknown sample UV spectra by the direct calibration technique. The results indicate that with the help of ridge trace analysis and ridge regression, the parameter k can be selected to obtain estimation of the colinearity of a system based on the stability of relative concentration as a function of k. Much information about the system to be analyzed can be obtained, such as whether there is colinearity among the variables, which measurement wavelength range is suitable for performing quantitative analysis, which components cannot be measured and which components can only be measured as a sum, and whether the quantitative model is correct.
authors.affiliation: Department of Chemistry and Chemical Engineering, Hunan University, Changsha 410012, People's Republic of China.
authors.lastname: Wei Wanzhi
authors.lastname: Zhu Wenhong
authors.lastname: Yao Shouzhuo