QUANTITATIVE-DETERMINATION OF OXALATE AND OTHER ORGANIC-ACIDS IN DRINKING-WATER AT LOW MU-G L CONCENTRATIONS/

In this research, a recently developed ion chromatography method for o rganic acids was expanded to include oxalate. A major challenge was th at oxalate elutes between inorganic anions such as sulfate, phosphate, bromide and nitrate, which are often present in much higher concentra tions than oxalate. Optimization of the previously reported method mad e it possible to determine oxalate in these matrices. However, for tho se samples in which higher inorganic anion concentrations caused the o xalate peak to be obscured, a ''heart-cut'' column switching technique was used as an alternative. The method detection limit for oxalate wa s 9 mu g/l with the direct approach and 6 mu g/l for the ''heart-cut'' technique. These modifications represent a valuable supplement to a r ecently developed method for monitoring ozonation by-products in drink ing water. (C) 1998 Elsevier Science B.V.