Lead Determination by Microwave-Assisted Inductively Coupled Plasma Optical Emission Spectrometry for RoHS Compliance

A microwave-assisted inductively coupled plasma optical emission spectrometry (ICP-OES) has been studied to evaluate its suitability to the certification of trace toxic element Pb in electronic and electrical equipment (EEE) in order to comply with RoHS regulation by EU council. In this contribution, a typical T-P and P-P digestion procedures were developed to evaluate efficiency of sample preparation and compatibility with ICP-OES analyzer. By determining Pb in a button cell using the proposed method, it found that the sample failed to comply with RoHS directive where maximum concentration value (MCV) of Pb is 1000 ppm. The spiked recoveries of samples with adding 2 mg kg^-1 Pb standard solution was in the range of 90-110%, which showed that the projects for sample preparation has a moderate compatibility with ICP-OES analyzer and high extraction competence. By studying the possible changes on spectral signals depending on the extraction procedure used, the optimal extraction project with maximum extraction efficiency is obtained. ICP-OES as a tool to determine trace lead has a high precision of R.S.D less than 3% and the repeatability less than 15%. It also provides with a very fast analysis (only 2-6 minutes for every sample) and a good project for meeting the need of RoHS compliance.