Quantitative spectroscopic analysis of heterogeneous systems: Chemometric methods for the correction of multiplicative light scattering effects

摘要

Owing to the high measuring speed and requirement of less or even no sample preparation, spectroscopic technologies have been increasingly applied in areas of food technology, agriculture, and pharmaceutics where heterogeneous samples are more frequently encountered than homogeneous ones. For heterogeneous samples, the potential uncontrolled variations in optical path length due to the physical variations such as particle size and distribution, shape and sample packing may cause dominant multiplicative light scattering perturbations which will mask the spectral variations related to the content differences of chemical compounds in samples and hence deteriorate the accuracy and reliability of quantitative spectroscopic analysis. Consequently, with a view to improve the accuracy and reliability of spectroscopic analysis for heterogeneous samples, a number of chemometric techniques have been developed to correct for the effects of multiplicative light scattering. This paper reviews currently available correction techniques for absorption spectroscopy with emphasis on their theories, limitations, and suitability for practical applications.