摘要
研究了在酸性介质中，铬（Ⅵ）在过量Ｆｅ（Ⅱ）存在下被完全还原为铬（Ⅲ），而余下的Ｆｅ（Ⅱ）在ＨＡｃ－ＮａＡｃ缓冲体系（ｐＨ４．６０）中与邻二氮菲生成桔红色的络合物，溶液的颜色随铬（Ⅵ）量的增加而呈线性降低，借此建立了吸光光度测定铬的新方法。其最大吸收波长为５１０ｎｍ，表现摩尔吸光系数为３．１１×１０４Ｌ·ｍｏＬ－１·ｃｍ－１，铬量在０～０．８ｍｇ／Ｌ范围服从比尔定律。方法简单、快速、灵敏度高，选择性好。在用于测定淤泥中微量铬时。
This paper discusses the chromium (Ⅵ) completely by excess lron(Ⅱ). The remaiming part lron(Ⅱ) reacts with 1-10-phenanthroline to form an orange-red complex in HAc-NaAc (pH4.60). The colour of complex has been to be directly inversely proportional to amount of chromium. The maxium absorptivity wavelength is at 510nm, and its apparent molar absortivily is 3.11×10 4L.mol -1 .cm -1 . Beers law is obeyed from 0 to 0.8mg/L of chromium (Ⅵ). The method is satisfactorily used for the determination of chromium in sludge.
关键词
铬
吸光光度法
淤泥
测定
chromium
spectrophotometric method
sludge
