UV-visible Spectroscopy

Many molecules absorb ultraviolet or visible light. The wavelength that is absorbed depends on the chemical composition and the intensity of the band is directly proportional to the concentration of an absorbing group or molecule. UV-visible spectroscopy enables the characterisation of functional groups in a molecule as well as the determination of their concentration. It is widely applied in environmental analysis, purity assessment and investigation of chemical reactions

The Green Chemistry lab is equipped with a Jasco V550 UV/VIS spectrophotometer, which has a wavelength range of 190 to 900nm provided by a deuterium lamp and a tungsten iodine lamp. It is fully PC controlled and is capable of scanning speeds of 10-4,000nm/min. Apart from the standard liquid cell module the instrument is also equipped with a solid sample holder for Diffuse Reflectance UV-visible studies. The high throughput optics combined with modern electronic design provide excellent sensitivity and stability. We use this instrument for routine structural and composition analysis, following the progress of chemical reactions, conversion rates and yields, and for polymer and material studies, including determination of catalytic species and loadings on solid supports, determination of type and level of material/polymer modification or degradation, and surface polarity measurements using probe molecules.