痕量Ni(Ⅱ)的4-(5-氯-2-吡啶偶氮)-1,3-二氨基苯显色树脂相分光光度法测定

Determination of Trace Ni(Ⅱ) by Resin - phase Spectrophotometry with 4 -(5 - Chloro - 2-pyridylazo) - 1,3-diaminobenzene

在pH9.0碱性介质中,Ni(Ⅱ)定量地交换吸附在负载了4_(5_氯_2_吡啶偶氮)_1,3_二氨基苯的强酸性阳离子交换树脂上而显色,可进行树脂相分光光度法测定痕量Ni(Ⅱ),最大吸收波长λmax=535nm,表观摩尔吸光系数ε=1.2×105 L·mol-1·cm-1,Ni(Ⅱ)量在0～0.44mg/L范围内符合比尔定律,用该法测定水样中痕量Ni(Ⅱ) ,结果令人满意。

A method for the determination of Ni(Ⅱ) by resin _ phase spectrophotometry with 4 _ (5 _ chloro _ 2 _ pyridylazo) _ 1,3 _ diaminobenzene is described. In the base medium of pH 9.0, Ni(Ⅱ)can be quantitatively adsorbed on the strong acid cation exchange resin loading 4 _ (5 _ chloro _ 2 _ pyridylazo) _ 1,3 _ diaminobenzene and a colored complex is formed with a maximum absorption wavelength at 535 nm and apparent molar absorptivity of 1.2×105 L·mol-1·cm-1. The Beer's law is obeyed in the range of 0～0.44 mg/L for Ni(Ⅱ). The proposed method was applied to the the determination of trace Ni(Ⅱ) in water samples with satisfactory results.