ultra-violet visible spectrophotometry
(uv-vis) [Te]
A method for determining the chemical composition of materials. Based on the same principle as , a beam of light is passed through a sample such that the amount of light absorbed is proportional to the concentration of the chemical under investigation. It can be used either to scan through a range of wavelengths from the ultra-violet to the visible or to analyse at one wavelength. Typical applications include the analysis of phosphates in soil extracts (where the phosphate is made to form a blue-coloured complex which absorbs in the visible region), the determination of iron and aluminium levels in soil, or the chemical composition of ancient glass.



