Ultraviolet absorption spectra of all 209 polychlorinated biphenyls evaluated by principal component analysis

The ultraviolet absorption spectra of all 209 polychlorinated biphenyls (PCBs) were recorded in the range 200-300 nm and displayed two important absorption maxima, viz., the main-band, lambda(max) 200-225 nm, and the kappa-band, lambda(max) 245-265 nm. By utilising principal component analysis, substitution related spectral characteristics of the PCBs, underlying the main patterns of the spectra, were examined. Captured in the multivariate evaluation were e.g., the importance of chlorine atoms in ortho positions, determining the intensity and existence of the kappa-band, chlorine substitution in para-para position, and the total number of chlorine atoms. The measured UV-spectra of all 209 polychlorinated biphenyls provide important physico-chemical descriptors for use in future quantitative structure-activity and structure-property relationship (QSAR/QSPR) studies.