SDG分离富集-1-(5-溴-2-吡啶偶氮)-2-萘酚-6-磺酸光度法测定环境样品中的微量镍

Spectrophotometric Determination of Nickel in Environmental Samples with 1-(5-Bromo-2-pyridylazo)-2-naphthol-6-sulphonic Acid by sulfhydryl Dextran Gel for Separation and Enrichment

研究了镍与５－Ｂｒ－ＰＡＮ－Ｓ的显色条件。在ｐＨ６．０的缓冲液中，形成１：２型的稳定配合物，配合物的最大吸收峰位于５７０ｎｍ波长处，表观摩尔吸光系数ε＝４．６９×１０４Ｌ／（ｍｏｌ．ｃｍ）。镍量在０～３０μｇ／２５ｍＬ范围内符合比尔定律。采用巯基葡聚糖凝胶分离干扰离子富集镍，提高了方法的选择性。

The condition of colour reaction of nickel with 1-(5-bromo-2-pyridylazo)-2-naphthol-6-sulphonic acid (5-Br-PAN-S) has been studied. Nickel forms with 5-Br-PAN-S a 1:2 stable complex in pH6.0. The maximum absorbance of the complex is at 570 nm and its apparent colar absorptivity is 4.6910 4 L/molcm. Beer's law is obeyed in the range of 030 g/25mL for nickel. The common metal ions can be separated, and to enrich nickel by sulfhydryl dextran gel, thus, greatly improving the selectivity and sensitivity of the system.