Total Organic Carbon (TOC) is a commonly employed technique for a non-specific indication of the total amount of organic species present in a sample. This is especially useful in E & L analyses where a measure of the total extractable organic species is desired but can’t be accomplished with a non-volatile residue analysis due to salt in the matrix. Other applications include indicating the water cleanliness in waste-water management, pharmaceuticals, and electronics manufacturing.
Organic carbon is oxidized to CO2 by persulfate in the presence of UV light. The TOC analyzer utilizes a UV lamp submerged in a gas-purged reactor filled with persulfate solution. Samples are introduced into the reactor, where CO2 is continuously removed from solution by the gas stream and carried to an infra-red detector tuned to the absorptive wavelength of CO2. The areas of the peaks produced are then compared to a calibration standard to provide a total organic carbon value in mg/L. Typical detection limits for this analysis are high ppb – low ppm levels.
Applications of this technique include:
- Total organic extractables in high-salt matrix for extractables and leachables
- Water cleanliness in industry , pharmaceuticals, and electronics
- Drinking water quality
