The Determinations of Pb, Cd, Hg, Cr6+, PBBs/PBDEs to Comply with RoHS Directive

For RoHS compliance, a method coupled inductively coupled plasma-optical emission spectrometry (ICP-OES), gas chromatography-mass spectrometry (GC-MS), and UV-visible spectrophotometry with microwave technology was developed to determine trace Cd, Hg, Pb, Cr⁶⁺, PBBs/PBDEs in electronic and electrical products (EEP). Elements were screened by Energy dispersion X-ray fluorescence spectrometry (EDXRF). In order to achieve good performance, other methods such as colorific test, inter-element correction (IEC) and standard addition techniques etc. were performed. By this study, it showed that analyses of Hg, Cd, Pb by ICP-OES and Cr⁶⁺ by UV-visible spectrophotometry had a RSD <5%, and a RSD <1% for PBBs/PBDEs by GC-MS analyzer. UV-visible spectrophotometry offered a good alternative for Cr⁶⁺ determination with alkali digestion, the inferences from Fe³⁺, Pb²⁺ etc. were eliminated by K₂HPO₄ buffer. The ramifications from monoBB/BDE to DecaBB/BDE were distinctly separated and successfully determined in the optimized condition. Furthermore, microwave system did an excellent job of consistently putting solid samples into solutions and had a moderate compatibility with spectrometric analyzer due to good recoveries. Though RSD of XRF screening was larger than 10%, it proved to be an easier, cheaper, faster technique. Because of the combination of multiple methodologies, the restricted substances can be determined with good precision and high reliability. It provides a prominent project for EE industries to comply with RoHS compliance.