Water in Liquid Hydrocarbons, and Heavy Hydrocarbons by Vaporizer, using Coulometry

This method is for determining the water content of liquid hydrocarbons (naphtha, gasoline, kerosene, diesel), or other petroleum products (sulfolane and other solvents) that are liquid at room temperature using coulometric Karl Fisher titration. The lower limit of quantitation for the titrator is 10 μg of water. This results in an applicable concentration range for a sample of 10 mg/kg (massppm) to 2 mass-% water.

Heavy hydrocarbons (insoluble oils and waxes) and other hydrocarbons that are viscous or solid at room temperature can be accommodated using a vaporizer for determining dissolved trace water and is applicable to samples over a concentration range of 20 mg/kg to 2 mass-% water.

Samples containing less than 500 mg/kg of water can be collected in prepared dry bottles or syringes as described in the Appendix.

Other applications for moisture and common interferences are discussed in Notes 1 and 2.