柱后衍生离子色谱法同时测定水中Fe^3＋,Fe^2＋,Cu^2＋,Zn^2＋方法研究

将Dionex 4000i离子色谱仪和国产721分光光度计组合联用,建立了一种同时测定水中Fe~(3+)、Fe~(2+)、Cu~(2+)、Zn~(2+)四种金属离子的柱后衍生离子色谱法。以磺基水杨酸/酒石酸/草酸为络合剂,质子化的二价乙二胺离子(EnH_2~(2+))为淋洗离子,在Dionex HPIC-CS2分离柱上先实现混合金属离子的分离,之后,各被分离的离子依次进入柱后反应器,与PAR在此反应显色生成有色络合物。借助国产721分光光度计,在500 nm的固定波长下依次检测流出的各离子。Fe~(3+)、Fe~(2+)、Zn~(2+)三种离子仅需6 min就可全部淋洗出。Cu~(2+)在切换淋洗液后检测,也仅需10 min。本法可用于同时测定天然水(mg/L级浓度)和电站高纯水(μg/L级浓度)以及金属腐蚀产物中的Fe~(3+)、Fe~(2+)、Cu~(2+)、Zn~(2+)。进样分析前,仅需将水样酸化和过滤即可。

Simultaneous Determination of Fe~(3+),Fe~(2+),Cu~(2+) and Zn~(2+) in Water by Ion Chromatography with Post-column Derivatization

Fe~(3+), Fe~(2+), Cu~(2+) and Z_n~(2+) water can be separated by ion chromatography in a column ofDionex CS-2, using mixed complexing agent solution of sulfosalicylic acid, tartaric acid, and oxalicacid, and an eluent of protonated ethylenediammonium ion (EnH_2~(2+)). The separated ion reactwith PAR in the post-column reactor consecutively and the colour thus formed are measuredspectrophotometrically. Environmental water and high purity waters of power plant have beenanalyzed by this method.