Greening Analytical Chemistry by Chemometrics

Abstract

Progress in recognising chemometrics as a way of greening chemical analysis has been moderate. This approach is highly relevant to green analytical chemistry because it reduces or can even remove the need for conventional chemical analysis. A typical chemometric method is multivariate decomposition, which can determine the concentration and spectra of individual compounds in a mixture even when the component spectra/concentration profiles overlap. Similarly, the aim of another chemometric method – principal component analysis (PCA) – in examining the relationships between samples (patients, food samples, organisms, chromatographic columns, spectra) and variables (compound concentrations, spectral peaks, chromatographic peak areas, elemental compositions) is to decompose the initial data table into simple components that can be represented graphically, thus allowing the relationships between objects to be easily visualised. Design of Experiments (DOE) is a chemometric method that could contribute significantly to the greening of analytical chemistry. Compared with the conventional approach to optimising the response of the instrument, whereby one factor at a time is varied while the others are kept constant, DOE drastically reduces the number of experiments required to determine the optimal value of each factor. Finally, this chapter provides a description of the ways in which flow techniques can be improved by computerised multiple input.