Detection of naphthalene sulfonates from highly saline brines with high-performance liquid chromatography in conjunction with fluorescence detection and solid-phase extraction

Abstract

A procedure is developed for the simultaneous determination of 1-naphthalene sulfonate, 2-naphthalene sulfonate, 1,5-naphthalene disulfonate, 1,6-naphthalene disulfonate, 2,6-naphthalene disulfonate and 2,7-naphthalene disulfonate from highly saline geothermal brines using ion-pair high-performance liquid chromatography with fluorescence detection after solid-phase extraction. The substances are baseline separated within 33 min and recoveries in brines with salinities of up to 175 g/L NaCl are 100% (± 10) by solid-phase extraction. For the overall method, the method quantification limits of the analytes are between 0.05 and 0.4 μg/L. The method is also shown to be feasible for matrices encountered in deep geothermal reservoirs. © The Author [2012].