Skip navigation

Analyzing Raman maps of pharmaceutical products by sample-sample two-dimensional correlation

Analyzing Raman maps of pharmaceutical products by sample-sample two-dimensional correlation

Sasic, Slobodan, Clark, Donald A., Mitchell, John C. ORCID: 0000-0003-2945-3292 and Snowden, Martin J. ORCID: 0000-0002-1087-2692 (2005) Analyzing Raman maps of pharmaceutical products by sample-sample two-dimensional correlation. Applied Spectroscopy, 59 (5). pp. 630-638. ISSN 0003-7028 (Print), 1943-3530 (Online) (doi:

Full text not available from this repository.


Sample-sample (SS) two-dimensional (21)) correlation spectroscopy is applied in this study as a spectral selection tool to produce chemical images of real-world pharmaceutical samples consisting of two, three, and four components. The most unique spectra in a Raman mapping spectral matrix are found after analysis of the covariance matrix. (This is obtained by multiplying the original mapping data matrix by itself.) These spectra are identified by analyzing the slices of the covariance matrix at the positions where covariance values are at maxima. Chemical images are subsequently produced in a univariate fashion by visually selecting the wavenumbers in the extracted spectra that are least overlapped. The performance of SS 2D correlation is compared with principal component analysis in terms of highlighting the most prominent spectral differences across the whole data set (which typically comprises several thousand spectra) and determining the total number of species present. In addition, the selection of the unique spectra by SS 2D correlation is compared with the selection obtained by the orthogonal projection approach (OPA). Both comparisons are found to be satisfactory and demonstrate that a quite simple SS 2D correlation routine can be used for producing reliable images of unknown samples. The main benefit of using SS 2D correlation is that it is based on a few data processing commands that can be executed separately and produce results that are closely related to the chemical features of the system.

Item Type: Article
Uncontrolled Keywords: Raman maps, pharmaceutical products, two-dimensional correlation, 2D correlation, sample-sample
Subjects: Q Science > QD Chemistry
R Medicine > RS Pharmacy and materia medica
Faculty / Department / Research Group: Faculty of Engineering & Science
Related URLs:
Last Modified: 16 Apr 2020 13:26
Selected for GREAT 2016: None
Selected for GREAT 2017: None
Selected for GREAT 2018: None
Selected for GREAT 2019: None
Selected for REF2021: None

Actions (login required)

View Item View Item