Automatic TIC/TOC Determination by TOC Difference Method in Hydrophobic Shale Sands

Shale Oil & Gas
Oral Presentation

Prepared by O. Buettel, S. Sun
Analytik Jena US, 100 Cummings Center, suite 234-N, Beverly, MA, 01915, United States

Contact Information: [email protected]; 781-376-9899


The parameters TOC (total organic carbon) and TIC (total inorganic carbon) are of interest in different applications and markets. These sum parameters are important in monitoring of starting products, e. g. for ceramic material, and for the classification of waste for landfills. Especially in landfills the evaluation of the organic compounds is important, because the classification of waste is based in the TOC value. The parameter TOC is therefore determined according to different norms, e. g. EN 13137 or EN15936. But also in other applications the TIC and TOC values are of interests. For mining products a fast and reliable method to distinguish between these two parameters is also important. Whether the carbon content derives from carbonates or from combustible organic material is a quality characteristic of the mined or extracted material.

The determination of TOC can be performed by a direct method where an aliquot of the sample is acidified directly in a ceramic boat with a diluted hydrochloric acid. Carbonates will react with the acid and form gaseous CO2. Afterwards the sample is dried and measured for the remaining TOC. Furthermore, to test for a complete reaction of the carbonate, the sample has to be acidified a second time until no gas will be produced any more. This is a long and laborious process. A more convenient approach is the acidification within the analyzer and the direct determination of the released CO2 from inorganic carbon.

In combination with a total carbon (TC) measurement the TOC can be calculated: TOC = TC – TIC. This automatic TOC difference method is performed with the Analytik Jena multi EA 4000 in combination with a TIC automatic module. For most matrices this automatic approach will work perfectly. Sand, soil and other inorganic material will be wetted by the acid fast and react completely.