Sample Preparation Tool for Voltammetry, Spectroscopy and Ion Chromatography  

The 705 UV Digester from Metrohm (UK) is suitable for sample pre-treatment in voltammetric, spectroscopic and ion chromatography determinations.

Electrochemical methods such as Voltammetry can suffer badly from interference from organic species if these are initially present in the sample matrix. Digestion by UV photolysis is based on the photolytic generation of OH radicals, which in turn react with organic compounds and degrade them. Hydrogen peroxide is used as an initiator of the radical reaction. The radiant energy of the mercury lamp is converted to heat and this accelerates the digestion. The UV Digester has also been used successfully as an analytical tool in Ion Chromatography determinations and the inorganic/organic ions are oxidised by generation of OH radicals.

The instrument has been designed for the digestion of water samples free from suspended matter that contain low to moderate concentrations of organic material such as natural surface waters. Owing to their low content in heavy metals, these samples are very sensitive to contamination. The advantage of UV photolysis is that only little hydrogen peroxide has to be added and consequently the blank values can be kept very low.