Total petroleum hydrocarbons (TPH) determination in surfactant stabilized marine water emulsions

Bilge waters are wastewaters produced on boats during navigation and usually contain hydrocarbons and oils. They cannot be released into the sea if not below certain hydrocarbon concentration limits set by current legislation. Surfactants are often used to improve the solubility of petroleum hydrocarbons in water and in this work, the analytical approach proposed is suitable to determine accurately the concentration of hydrocarbons in surfactant-rich waters, as found in bilge water or similar wastewater. The method relies on the surfactant precipitation by addition of potassium and calcium salts, which also promote TPH extraction through a “salting out” effect. This allows for an accurate determination of total petroleum hydrocarbons (TPH) by a GC-MS/MS approach, which reduces any matrix/surfactant interference to a negligible extent.