Gilsonite contents

Carbon, Hydrogen, Nitrogen, Sulfur and Oxygen in Bitumen

Carbon and hydrogen

The measurements of carbon and hydrogen in the Gilsonite are done on very small samples, and therefore the test must be done with sufficient accuracy.

The sample is completely burned in oxygen at 800 degrees Celsius.

The combustion products pass through warm copper oxide and convert all the remaining carbon and hydrogen into CO2 and H2O, respectively.


The amount of nitrogen in the bitumen is measured by the famous Kjeldahl method.

Sulfur has various forms in bitumen. To measure total sulfur in bitumen, dissolve a gram bitumen with a mixture of a portion of sodium carbonate-free water and two parts of dilute magnesium oxide and heat it.
To determine the amount of mineral sulfur in the bitumen, which is in the form of sulfate, it dissolves the chloride acid and precipitates in the form of barium sulfate and weighs the resulting precipitate.

The amount of organic sulfur will be obtained from the difference in total weight of sulfur and sulfur minerals.

The amount of oxygen in the bitumen cannot be measured directly by any reliable method.

To determine the amount of this element, first all the components in the bitumen are carefully measured according to the above methods, and their total difference of 100 equals to the bitumen oxygen content.