FLOW-INJECTION ANALYSIS OF ORGANIC AND INORGANIC CARBON IN THE LOW-PPB RANGE

A cylindrical thin-film reactor with an actively rotating inner cylinder and a central low-pressure mercury lamp can be used for the continuous determination of organic carbon (OC) and inorganic carbon (IC) in the low mu-g/L concentration range. The separation of inorganic carbon is performed in the upper UV-shielded part of the reactor by continuous acidification. In the lower part the sample is exposed to UV irradiation and organic carbon is converted into carbon dioxide. The carbon dioxide released in both processes is quantified by high-sensitivity infrared spectrometry. The linear range is about 3 orders of magnitude. Owing to the low dead volume, the reactor can be used as an organic carbon detector for liquid chromatography (LC, HPLC). Furthermore, the oxidized reactor outflow can be used for further analyses. The first prototype of the reactor was developed by a private company in 1980. Since then it has constantly been improved. This is the first publication on the reactor since 1983.