Isotope dilution thermal ionization mass spectrometry was used to obtain the certified lead concentration of SRM 2582 and a rigorous digestion with nitric, hydrofluoric and perchloric acids was used. The digestion method used to prepare samples for ICP-OES analysis was also very rigorous and involved a microwave digestion with nitric and hydrofluoric acids followed by wet-ashing with perchloric acid. Many customers have difficulty with this material as it is not easy to digest. The CPSC is using a digest based on AOAC 974.02 (see http://www.cpsc.gov/about/cpsia/CPSC-CH-E1003-09.PDF). Our experience has been that you need to evaporate the digest to dryness several times with nitric acid before bring it back up into solution.