Abstract: The complexes of metal (Fe (III), Cu, Pb, Zn and Mn) and ［S,S′］-ethylenediaminedisuccinic acid (EDDS)in plants and soils were determined by using ion chromatography and electrospray ionization mass spectrometry. The separation of metal-EDDS complexes was carried out using the Dionex IonPac AS11-HC column (250 mm×4.2 mm, 5 μm) with guard column. The mobile phase was 60 mmol/L ammonium nitrate solution at pH 6.5, the flow rate was 1.0 mL/min, and the detection wavelength was 260 nm. The mass spectrometry identification of metal-EDDS complexes was performed by using selected ion monitoring (SIM) mode. The results showed that method can be used for Fe(III)-, Pb-, Cu-EDDS complex determination and the detection limits of Fe(III)-, Pb- and Cu-EDDS complexes were 0.38, 0.54 and 0.18 μmol/L. and the recoveries were 99.6%, 100.6% and 97.5%, respectively. The method is simple, sensitive and suitable for either single or simultaneous analysis of Fe(III)-, Cu- and Pb-EDDS complexes in plants and soils.

Key words: electrospray ionization mass spectrometry （ESI-MS）, metal-［S,S′］-ethylenediaminedisuccinic acid complexes, plants, soils , ion chromatography （IC）