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

在pH8．0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545nm，在15-500μg·L^-1范围内共振散射增强强度（△I）与镍（Ⅱ）质量浓度呈线性关系。检出限（3S／N）为4．57μg·L^-1，分别对50，200，400μg·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％。

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 （△I） was found keeping linear relationship with the concentration of Ni（Ⅱ） ion in the range from 15--500μg·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. 57μg·L^-1. Precision was tested at 3 concentration levels of 50, 200,400μg 2L^-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%.