植物及土壤中乙二胺二琥珀酸金属复合物的离子色谱分析与质谱鉴定

利用阴离子交换色谱柱及紫外-可见光检测器建立的离子色谱分析方法对植物及土壤中乙二胺二琥珀酸(［S,S′］-ethylenediaminedisuccinic acid,EDDS)金属(Fe(III)、Pb、Cu、Zn和Mn)复合物进行了分析,并用电喷雾质谱对其进行了确认。实验选用戴安IonPac AS11-HC阴离子交换色谱柱(250 mm×4.2 mm,5 μm)及保护柱,以60 mmol/L硝酸铵溶液(pH 6.5)为洗脱液,在1.0 mL/min流速下进行等度洗脱,检测波长为260 nm。金属-EDDS复合物的质谱鉴定采用选择离子扫描模式。结果表明,该方法可以用于Fe(III)-、Pb-、Cu-EDDS复合物的分离测定,三者的检出限分别是0.38,0.54和0.18 μmol/L,回收率分别是99.6%,100.6%和97.5%。该方法操作简单、灵敏,适合于植物样品及土壤样品中含有的Fe(III)-、Cu-和Pb-EDDS复合物的单独或同时分析鉴定。

Ion chromatographic analysis and mass spectrometric identification of complexes of metal and ethylene- diaminedisuccinic acid in plants and soils

The complexes of metal (Fe (Ⅲ), Cu, Pb, Zn and Mn) and 5,5']-ethylenedia-minedisuccinic 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 identifica-tion 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 determina-tion 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.