The TOC-L series of TOC analyzers adopts the 680°C combustion catalytic oxidation method, which was developed by Shimadzu and is now used worldwide. While providing an ultra wide range of 4 μg/L to 30,000 mg/L, these analyzers boast a detection limit of 4 μg/L through coordination with NDIR. This is the highest level of detection sensitivity available with the combustion catalytic oxidation method. In addition, the combustion catalytic oxidation method makes it possible to efficiently oxidize not only easily-decomposed, low-molecular-weight organic compounds, but also hard-to-decompose insoluble and macromolecular organic compounds.