Complete digestion of a sample is critical for accurate elemental analysis using inductively coupled plasma - atomic emission spectroscopy (ICP-AES). ICP-AES is a very versatile instrument that can be used to analyze a broad range of materials. Analysis is not limited by sample size, shape, or material as it is with other instrumentation such as Arc/Spark OES. Applications for utilizing ICP range from determining high elemental concentrations needed for alloy identification to trace analysis required for ensuring purity or compliance with health and environmental mandates.

A recent directive by the European Union regarding restriction of hazardous substances (RoHS) restricts the concentration of lead, mercury, cadmium, hexavalent chromium, polybrominated biphenyls, and polybrominated diphenyl ethers in electrical and electronic equipment. While XRF is emerging as the primary screening method for RoHS, ICP-AES is likely to be the methodology used to confirm cadmium and lead compliance when a sample is in question. ICP analysis of heavy metals has been well documented in the environmental sciences, but analyses for these elements in complex matrices found in electronic equipment such as metal alloys, plastics, resins, glasses, and ceramics is still currently without standardized methodology. Many materials are readily soluble with a combination of acids at reasonable temperatures and atmospheric pressure. However, a large number of materials require more intense digestion conditions including salt fusions or temperatures and pressures unattainable on a hotplate. Methods for digestion of the complex materials described above and other aspects of ICP analysis of these materials will be discussed.