以2,2′,4,4′-四羟基二苯甲酮为配体分光光度法测定痕量镍

Determination of Trace Nickel by Spectrophotometry with 2,2′,4,4′-Tetrahydroxybenzophenone as Ligand

摘要: 以2,2′,4,4′-四羟基二苯甲酮(BP-2)为配体,采用分光光度法测定痕量Ni2+。在pH 9.80的硼酸-氯化钾-氢氧化钠缓冲溶液中,BP-2与Ni2+在60 ℃下反应20 min后,生成络合物,其最大吸收波长在434 nm,摩尔吸光率为2.025×104L·mol-1·cm-1。Ni2+的质量浓度在0.20~23.0 mg·L-1范围内与吸光度呈线性关系,检出限(3S/N)为0.17 mg·L-1。加标回收率在99.3%~103%之间,测定值的相对标准偏差(n=6)在1.1%之内。采用此方法测定含Ni2+废液中的Ni2+,结果与原子吸收光谱法的测定结果的相对误差为-0.98%。

Abstract: Spectrophotometry was applied to the determination of trace Ni2+ with 2,2′,4,4′-tetrahydroxybenzophenone (BP-2) as a ligand. In the buffer solution of H3BO3-KCl -NaOH (pH 9.80), Ni2+ reacted with BP-2 at 60 ℃ for 20 min to form a complex, which displayed the maximum adsorption at the wavelength of 434 nm with the molar absorptivity of 2.025×104L·mol-1·cm-1. A linear relationship was found between the absorbance and the mass concentration of Ni2+ in the range of 0.20-23.0 mg·L-1, with detection limit (3S/N) of 0.17 mg·L-1. Recovery rates obtained by standard addition method were in the range of 99.3%-103% and RSDs (n=6) were within 1.1%. The proposed method was used to determine Ni2+ in waste solution, the relative error was -0.98% compared with AAS.