Innovations In UV Oxidation Direct Conductivity TOC Measurement To Improve Accuracy And Precision

By Roger Schmid and Randy Turner

Total Organic Carbon or TOC is the carbon whose origin is organic in nature. It can originate from naturally occurring organic acids, such as tannic acid, bacteria, and abrasion of valves. The measurement of TOC is critical to the pharmaceutical industry because various regulatory bodies have established limits for TOC in Water for Injection (WFI) and other uses of water in pharmaceuticals.

To measure TOC, the organic molecules must be reduced to inorganic carbon allowing quantitative measurement of the resultant carbon dioxide CO2. The organic molecule can be decomposed to inorganic carbon by thermal  decomposition, UltraViolet (UV)-persulfate oxidation, and direct UV oxidation.

The following are common methods of TOC analysis:
1. Thermal decomposition with NDIR detection
2. UV-persulfate oxidation with NDIR detection
3. UV-persulfate oxidation with conductivity detection
4. Direct UV oxidation with conductivity detection
 

This Article is published with permission from the International Society of Pharmaceutical Engineering (ISPE), and Pharmaceutical Engineering Magazine

This Article is published with permission from the International Society of Pharmaceutical Engineering (ISPE), and Pharmaceutical Engineering Magazine