印刷电路板中重金属含量的分析方法

Analysis Method of Heavy Metals in Printed Circuit Boards

以印刷电路板(PCB)中重金属含量准确分析为目的,研究了样品制备、消解温度控制、消解试剂等因素对金属元素提取效率的影响,得到针对PCB样品的微波消解预处理-电感耦合等离子体发射光谱仪(ICP-OES)分析检测技术.研究选取PCB中含量大、毒性高的As,Mn,Cr,Ni,Zn,Pb,Cu等7种金属为目标元素,优化后的HNO3,H2O2,HF(体积比为7:2:4)混合试剂微波消解技术能有效分解电路板基体,溶解待测物,分析结果准确,重现性较好.利用该方法对不同电器PCB进行分析,结果表明电路板中重金属元素含量高、差异大,其中Cu和Pb的质量分数分别高达27.1～441.0,0.2～29.0g.kg-1.

A method based on the coupling of microwave digestion and inductively coupled plasma-optical emission spectroscopy determination was developed for heavy metals in printed circuit board （PCB）. Detailed optimizations of sample preparation, digestion temperature setup and digestion regents usage were enabled to obtain the maximum extraction efficiency of metals from PCB samples. The recommended multi-reagent microwave digestion technology, in which the volumes of HNO3-H2O2-HF were 7 ml, 2 ml and 4 ml respectively, could decompose PCB matrix efficiently and dissolve heavy metals into solvent very well. By using the optimized method, the analysis results of practical PCB samples were accurate and reproducible. And the results show that the contents of heavy metals in different PCB samples are quite discrepant and the amounts of Cu and Pb are even up to 27.1-441 g · kg- 1 and 0.2-29 g · kg-1.