By combusting your sample in a stream of pure oxygen in a high temperature furnace and measuring the infra-red absorbance of the resulting gasses, carbon and sulfur content can be simultaneously determined. When performed directly on untreated pulp sample, the total carbon and sulfur can be established.

Carbon/Sulfur Speciation

When further information as to the chemical state of the carbon and sulfur components is desired, various pretreatments can be employed to speciate the results. Carbon may be present in rock samples as an organic material such as detritus, petroleum, coal or graphite, or as an inorganic such as a carbonate.

Upon exposure to dilute acid, many carbonate containing minerals will release their carbon as CO2, so if the residue is recovered and the remaining carbon content determined, it is often taken as a proxy for organic carbon. Similarly, the residue can be further treated with pyridine to distinguish graphitic and bituminous components.

Sulfur content in geological samples can be broadly divided into sulfide, sulfate and native sulfur. As with carbon speciation, various pretreatments can be used to help develop proxies for these different components such as roasting and sodium carbonate leaching.