痕量镍测定的新方法

A Novel Determination Method of Trace Nickel

在碱性条件下,Ni(II)和1-(2-吡啶偶氮)-2-萘酚(PAN)形成聚合物,对PAN的共振光散射有增强作用,加入十二烷基苯磺酸钠(SDBS)进一步敏化该体系.共振光散射增强强度(ΔI)与Ni(II)浓度呈良好的线性关系,据此建立了测定Ni(II)的共振光散射分析方法.在优化的实验条件下,体系的最大散射波长位于545nm处,方法的线性回归方程为ΔIRLS=4502.9ρ(μg/mL)+271.82;线性范围为15.2500ng/mL;相关系数γ=0.9975;检出限为4.57 ng/mL.对Ni(II)分别为50ng/mL、200ng/mL、400ng/mL低、中、高三个浓度进行11次平行测定,其相对标准偏差分别为:3.5%、3.0%和1.7%.

A resonance light scattering （RES） enhancement method is developed for the determination of nickel.The proposed method is based on the enhanced effect on the resonance light scattering of PAN after the formation of Ni - PAN complex in the presence of SDBS which acted as sensitizer in the alkaline medium. The maximum RLS wavelength is located at 545nm. Under optimal conditions, △I is proportional to the concentration of Ni^2＋ in the range of 15.2ng/mL - 500ng/mL, the linear regress equation is △IRLS = 4502.9ρ（△g/mL） ＋ 271.82（γ= 0.9975）, the detection limit is 4.57ng/mL, the relative standard deviation is 3.5%, 3.0% and 1.7% for the Ni^2＋ concentration of 50ng/mL, 200ng/mL and 400ng/mL, respectively.