Multivariate spectroscopic methods for the analysis of solutions

In this thesis some multivariate spectroscopic methods for the analysis of solutions are proposed. Spectroscopy and multivariate data analysis form a powerful combination for obtaining both quantitative and qualitative information and it is shown how spectroscopic techniques in combination with chemometric data evaluation can be used to obtain rapid, simple and efficient analytical methods. These spectroscopic methods consisting of spectroscopic analysis, a high level of automation and chemometric data evaluation can lead to analytical methods with a high analytical capacity, and for these methods, the term high-capacity analysis (HCA) is suggested. It is further shown how chemometric evaluation of the multivariate data in chromatographic analyses decreases the need for baseline separation. The thesis is based on six papers and the chemometric tools used are experimental design, principal component analysis (PCA), soft independent modelling of class analogy (SIMCA), partial least squares regression (PLS) and parallel factor analysis (PARAFAC). The analytical techniques utilised are scanning ultraviolet-visible (UVVis) spectroscopy, diode array detection (DAD) used in non-column chromatographic diode array UV spectroscopy, high-performance liquid chromatography with diode array detection (HPLC-DAD) and fluorescence spectroscopy. The methods proposed are exemplified in the analysis of pharmaceutical solutions and serum proteins. In Paper I a method is proposed for the determination of the content and identity of the active compound in pharmaceutical solutions by means of UV-Vis spectroscopy, orthogonal signal correction and multivariate calibration with PLS and SIMCA classification. Paper II proposes a new method for the rapid determination of pharmaceutical solutions by the use of non-column chromatographic diode array UV spectroscopy, i.e. a conventional HPLC-DAD system without any chromatographic column connected. In Paper III an investigation is made of the ability of a control sample, of known content and identity to diagnose and correct errors in multivariate predictions something that together with use of multivariate residuals can make it possible to use the same calibration model over time. In Paper IV a method is proposed for simultaneous determination of serum proteins with fluorescence spectroscopy and multivariate calibration. Paper V proposes a method for the determination of chromatographic peak purity by means of PCA of HPLC-DAD data. In Paper VI PARAFAC is applied for the decomposition of DAD data of some partially separated peaks into the pure chromatographic, spectral and concentration profiles. I Determination of the content and identity of lidocaine solutions with UVvisible spectroscopy and multivariate calibration Kent Wiberg, Anders Hagman, Peter Burén, Sven P. Jacobsson The Analyst 126 (2001) 1142-1148 In this paper the author is responsible for the idea, the design of the study, performing parts of the laboratory work, conducting the data modelling, and the writing of the paper. II Rapid determination of lidocaine solutions with non-column chromatographic diode array UV spectroscopy and multivariate calibration Kent Wiberg, Anders Hagman, Sven P. Jacobsson Journal of Pharmaceutical and Biomedical Analysis 30 (2003) 1575-1586 In this study the author created the design of the study, performed the laboratory work and the data modelling and wrote the paper. III Use of control sample for estimation of prediction error in multivariate determination of lidocaine solutions with non-column chromatographic diode array UV spectroscopy Kent Wiberg, Mattias Andersson, Anders Hagman, Sven P. Jacobsson Journal of Pharmaceutical and Biomedical Analysis 33 (2003) 859-869 In this work the author is responsible for the idea, the design of the study, performing the data modelling, and the writing of the paper. IV Simultaneous determination of albumin and immunoglobulin G with fluorescence spectroscopy and multivariate calibration Kent Wiberg, Agneta Sterner-Molin, Sven P. Jacobsson Talanta 62 (2004) 567-574 In this study the author created the design of the study, performed the data modelling and wrote the paper. V Peak purity determination with principal component analysis of highperformance liquid chromatography-diode array detection data Kent Wiberg, Mattias Andersson, Anders Hagman, Sven P. Jacobsson, Journal of Chromatography A 1029 (2004) 13-20 In this paper the author is responsible for the idea, the design of the study, performing the data modelling, and the writing of the paper. VI Parallel factor analysis of HPLC-DAD data for binary mixtures of lidocaine and prilocaine with different levels of chromatographic separation Kent Wiberg, Sven P. Jacobsson Analytica Chimica Acta, accepted for publication, March 2004 In this paper the author created the design of the study, performed the data modelling and wrote the paper. List of papers: