Determination of synthetic chelating agents in surface and waste water by ion chromatography–mass spectrometry

Coupling of ion chromatography with electrospray mass spectrometry (IC–MS) is a simple, sensitive and quick method for the determination of polar organic traces in water samples without derivatization. Analysis of the chelating agents ethylenediamino tetraacetate (EDTA) and diethylenetriamino pentaacetate (DTPA) in aqueous samples was done by IC–MS on an anion exchange column after simple sample preparation steps. Quantification down to a concentration level of 1 μg L−1 even in wastewater influents and effluents was achieved utilizing 13C marked internal standards and measuring the individual [M − H+]− and stable [M − 4H+ + Fe3+]− cluster ions. The method was validated against certified, but more time consuming routine methods. Applying this method a series of several European water samples were analyzed for EDTA and DTPA indicating their nature as polar persistent pollutants.