DETERMINATION OF INORGANIC-IONS IN OIL-FIELD WATERS BY SINGLE-COLUMN ION CHROMATOGRAPHY

A new method to determine inorganic ions in oil field water by single- column ion chromatography is presented. On an anion-bonded column, usi ng a mixture of sodium benzoate (1.5 mM) and sodium citrate (0.1 mM) a s eluent, the Cl-, NO3- and SO42- in oil field water can be determined . On a cation-bonded column, using 1.5 mM HNO3 as eluent, the Na+ and K+ in oil field water can be determined. If a mixture of oxalic acid a nd ethylene diamine (both at 1.5 mM) is used as the eluent, then Mg2+, Ca2+, Sr2+ and Ba2+ can be determined. If the content of Cl- and Nais much higher than that of other inorganic ions, the sample may be di luted to allow the determination of these ions. The proposed method is characterized by its simplicity, rapidity and accuracy. The results m atch those obtained with the current procedures used in oil fields. (C ) 1997 Elsevier Science B.V.