Our Total Oxidizable Carbon (TOC) test measures the amount of oxidizable carbon in the water (excluding carbon dioxide and carbonates). TOC is a measurement of organic acid, halogenic compounds and organic nitrogen whose presence in ultrapure water may negatively affect process yields. TOC serves as a source of food for bacteria, and originates from leachate from PVC pipes; solvents used to bond the PVC, or from contaminated source water. Bacteria, though definitive Organic Carbon, are rarely in ultrapure water at levels high enough to be a major portion of the measured TOC (0.002-10%).

Trimethyl amines, chloroforms, and urea are some of the organic material present in ultrapure water. A high sensitivity TOC analyzer that uses ultraviolet light, or ultraviolet light and persulfate, to breakdown organics to carbon dioxide is used to measure TOC levels. The measurement of the carbon dioxide can be effected by conductivity or by infrared spectrometry.

The lower detection limit for Total Oxidizable Carbon is 5ppb.