镍(Ⅱ)-1-(2-吡啶偶氮)-2-萘酚-十二烷基苯磺酸钠体系共振光散射法测定痕量镍
Resonance Scattering Spectrometric Determination of Trace Amounts of Nickel by Its Reaction with PAN Sensitized with SDBS
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摘要: 在pH 8.0的Tris-盐酸缓冲介质中,利用十二烷基苯磺酸钠(SDBS)增敏镍(Ⅱ)和1-(2-吡啶偶氮)-2-萘酚(PAN)形成离子缔合物体系,使体系共振光散射增强.体系最大散射波长545 nm,在15~500 μg·L-1范围内共振散射增强强度(ΔI)与镍(Ⅱ)质量浓度呈线性关系.检出限(3S/N)为4.57 μg·L-1,分别对50,200,400 μg·L-1镍(Ⅱ)标准溶液进行11次平行测定,测定值的相对标准偏差(n=6)依次为3.5%,3.0%,1.7%.据此提出了一种简单而快速的测定镍的方法.应用于测定水样中镍量,测得其平均回收率为98.5%.Abstract: Intensity of resonance scattering of the reaction between Ni(Ⅱ) and 1-(2-pyridylazo)-2-naphthol (PAN),in a Tris-HCl buffer medium of pH 8.0,was sensitized by sodium dodecylbenzene Sulfonate (SDBS),and the magnitude of increase in resonance rayleigh scattering intensity (ΔI) was found keeping linear relationship with the concentration of Ni(Ⅱ) ion in the range from 15-500 μg·L-1 when measured at 545 nm (the maximum scattering wavelength of the reaction system).Detection limit (3S/N) of the method was found to be 4.57 μg·L-1.Precision was tested at 3 concentration levels of 50,200,400 μg·L-1 of Ni(Ⅱ) for 11 determinations,values of RSD′s (n=6) found were 3.5%,3.0% and 1.7% respectively.Based on these facts,a simple and rapid method for determination of nickel was proposed.In its application to analysis of water samples for their nickel contents,value of average recovery found was 98.5%.