湿地土壤铁的分析测定方法比较

结合湿地土壤滞水缺氧特征，根据不同研究需要比较了现有常用的铁元素分析测定方法。通过比较发现，可用于湿地土壤铁分析测定的方法有10余种，其中全量测定以原子吸收光谱法或电感耦合等离子体发射光谱法在准确度、灵敏度和检出时间上优于各类比色法；BPDS-EDTA双络合紫外一可见分光光度法是能稳定铁价态并准确同时测定2种价态铁含量的最有效方法；鉴于湿地土壤明显的空间异质性，基于重金属分级研究而改进的连续浸提法优于经典的铁氧化物种类的独立区分；考虑到铁价态与种类的精确刻度对湿地环境变化研究的重要指征价值，价态区分与种类区分采用鲜土即时测定比风干土更能反映土壤的自然实貌。

Comparison of Analysis and Determination Methods of Iron in Wetland Soil

Available common analysis and determination methods of iron are compared considering the waterlogged and anoxic condition of wetland soils according to different research purpose.Comparative study shows that over 10 methods can be used in the iron determination of wetland soil;Atomic absorption spectrometry or inductively coupled plasma atomic emission spectroscopy-atomic emission spectrometry(ICP-AES)has advantages over colorimetric methods in accuracy,sensitivity and detection time;BPDS-EDTA dual-chelation spectrophotometry is the most effective method with which to stabilize Fe oxidation states and determinate Fe(II)and Fe(III)accurately and simultaneously;Sequential extraction of soil iron oxides is superior to the classic independent extraction in view of the obvious spatial heterogeneity of wetland soils;Immediate determination with fresh field soils is strongly recommended other than air-dried soils in order to better reflect the original condition of soil iron.