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

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Ni 2+。在pH9.80的硼酸-氯化钾-氢氧化钠缓冲溶液中,BP-2与Ni 2+在60℃下反应20min后,生成络合物,其最大吸收波长在434nm,摩尔吸光率为2.025×104L·mol-1·cm-1。Ni 2+的质量浓度在0.20~23.0mg·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Ni 2+废液中的Ni 2+,结果与原子吸收光谱法的测定结果的相对误差为-0.98%。

Spectrophotometry was applied to the determination of trace Ni 2+with 2,2′,4,4′-tetrahydroxybenzophenone(BP-2)as a ligand.In the buffer solution of H3BO3-KCl-NaOH(pH 9.80),Ni 2+reacted with BP-2at 60 ℃ for 20 min to form a complex,which displayed the maximum adsorption at the wavelength of 434 nm with the molar absorptivity of 2.025×104 L·mol-1·cm-1.A linear relationship was found between the absorbance and the mass concentration of Ni 2+in the range of 0.20-23.0 mg·L-1,with detection limit(3S/N)of 0.17mg·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 Ni 2+in waste solution,the relative error was-0.98% compared with AAS.