Analysis Method of Heavy Metals in Printed Circuit Boards

Abstract:

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.

Key words:printed circuit board; microwave digestion; sample pretreatment; heavy metals analysis