Analysis of Naphthenic Acids in Filtered Oil Sands Process Water (OSPW) using LC/TOF with No Sample Preparation

Naphthenic acids (NAs) are water soluble weak acids, with the general chemical formula CnH2n+zO2, where n is the carbon number, z is referred to as hydrogen deficiency, is a negative even integer and is the number of hydrogen atoms that are lost as the number of rings in naphthenic acid increases. More than one isomer will exist for a given z homolog and the molecular weights differ by 2 mass units (H2) between z-series and by 14 mass units (CH2) between n-series. The number of possible naphthenic acids, with the same molecular composition, are 134 with n ranging from 6 to 30 and the number of saturated rings ranging from 0 to 6. Fig.1 shows examples of the general structures of naphthenic acids which have a different number of rings1. Analysis of Naphthenic Acids in Filtered Oil Sands Process Water (OSPW) using LC/TOF with No Sample Preparation Liquid Chromatography/ Mass Spectrometry