ISO 10694:1995 Soil quality — Determination of organic and total carbon after dry combustion (elementary analysis)

ISO 10694:1995 specifies a method for the determination of the total carbon content in soil after dry combustion. The organic carbon content is calculated from this content after correcting for carbonates present in the sample. If carbonates are removed beforehand, the organic carbon content is measured directly. This method is applicable to all types of air-dried soil samples. 

The relevance of measuring these carbon parameters lies in their critical role in assessing soil quality and fertility. Organic carbon is a key component of soil organic matter, which influences soil structure, nutrient availability, and water retention. Total carbon includes both organic carbon and inorganic carbon (carbonates), providing a comprehensive measure of the soil's carbon content. The dry combustion method is important because it provides a reliable and accurate means of quantifying carbon levels in soil samples. 

The dry combustion process involves heating the soil sample to high temperatures in the presence of oxygen, causing the carbon compounds to oxidize and form carbon dioxide (CO₂). The CO₂ produced is then measured to determine the total carbon content. To determine the organic carbon content, present carbonates have to be removed by acid treatment before combustion, allowing for the direct measurement of organic carbon. The accuracy and reliability of this method are crucial for ensuring that soil quality assessments are thorough and that appropriate measures can be taken to manage and improve soil health.

With the multi EA 4000 we provide a perfectly suited analyzer to follow ISO 10694. The robust setup offers the ideal system for acidified soil samples and harsh sample matrices.

Sources

• ISO 10694:1995 - Soil quality — Determination of organic and total carbon after dry combustion (elementary analysis)