Trace analysis of fluorinated aromatic carboxylic acids in aqueous reservoir fluids by HPLC

A straightforward and reliable HPLC method is described, allowing the trace determination of 16 fluorinated aromatic carboxylic acids in aqueous reservoir fluids. Thirteen of these tracer compounds can be determined simultaneously. Concentrations as low as 10 mu g/L were determined for selected acids in aqueous reservoir fluids, without sample preparation. The reversed phase column retarded the natural organic background present in aqueous reservoir samples until the selected tracer compounds had been eluted from the column. The use of a diode array detector enabled the identification of the fluorinated benzoic acids. The described technique was used for the reliable determination of the water tracers 2,6-difluorobenzoic acid, 2-fluorobenzoic acid and 3-fluorobenzoic acid in aqueous reservoir samples from a North Sea reservoir.