摘要
旨在建立一种适用于复杂锌镍合金镀液体系的锌离子精确定量方法,以突破传统分析技术在该领域的局限性。针对锌镍镀液成分复杂、镍离子干扰显著及配位剂封闭效应等技术瓶颈,创新性地将库仑滴定法与优化标准加入法相结合,构建了基于[Fe(CN)_(6)]^(4-)-Zn^(2+)沉淀反应的电化学分析体系。该方法通过向待测样品中精确添加过量锌标准溶液,实现双重优化机制:其一,过量锌离子与溶液中共存镍离子形成竞争性沉淀,有效抑制镍离子对锌测定的干扰;其二,饱和配位剂浓度消除其对指示剂的封闭作用,从而省去传统方法的繁琐预处理步骤。通过构建锌标准溶液内标体系,建立库仑滴定终点时间与锌浓度的线性响应关系,采用内标换算方法消除溶液基质效应。研究结果表明,该优化方法不仅显著提高了锌镍镀液中锌含量测定的准确性和效率,还展现出对复杂工业样品体系的强适应性。通过双重控制策略(锌镍物质的量浓度比阈值≥10与标准锌物质的量添加比例1.5~5),成功解决了共沉淀干扰和配位剂封闭的行业难题。为电镀液在线监测技术的开发提供了理论基础,对提升锌镍合金电镀工艺的质量控制具有重要应用价值。
This study presented a novel analytical strategy for the precise quantification of zinc ion in complex zinc-nickel plating solutions,addressing the limitations of conventional techniques in this field.Targeting technical bottlenecks such as solution complexity,significant nickel ion interference,and ligand blocking effects,we integrated coulometric titration with an optimized standard addition method,establishing an electrochemical analysis system based on the[Fe(CN)_(6)]^(4-)-Zn^(2+)precipitation reaction.The dual optimization mechanism involved:(ⅰ)competitive precipitation,where excess zinc suppresses nickel ion interference,and(ⅱ)saturation of ligand binding sites to eliminate blocking of the indicator,thereby eliminating the need for tedious pretreatment procedures.By constructing an internal standard system using zinc standards enabled,a linear relationship between coulometric titration endpoint time and concentration was established,with matrix effects corrected through internal standard conversion algorithms.The optimized method not only significantly enhances accuracy and efficiency for zinc determination in industrial plating solutions,but also shows strong adaptability to complex industrial matrics.By implementing dual control strategies(Zn/Ni molarity ratio≥10 and standard addition ratio 1.5~5),we resolved co-precipitation interference and ligand blocking challenges.This work provides theoretical foundations for developing online monitoring technologies,offering practical value for enhancing quality control in zinc-nickel alloy electroplating processes.
作者
王岩
胡采薇
蔡俊钧
何芃
唐俊榕
程程
朱志伟
WANG Yan;HU Cai-wei;CAI Jun-jun;HE Peng;TANG Jun-rong;CHENG Cheng;ZHU Zhi-wei(National Demonstration Center for Experimental Chemistry Education,Peking University,Beijing 100871,China;College of Chemistry and Molecular Engineering,Peking University,Beijing 100871,China;Shanghai Aircraft Manufacturing Co.,Ltd.,Shanghai 201324,China)
出处
《化学试剂》
2025年第7期78-85,共8页
Chemical Reagents
关键词
锌镍镀液
锌含量测定
标准加入法
电分析
库仑滴定法
zinc-nickel plating solutions
zinc content determination
standard addition method
electroanalysis
coulometric titration
