Inductively Coupled Plasma Mass Spectrometry In The Analysis Of Electrical And Electronic Materials

Since February 13, 2003, RoHS (restriction of the use of certain hazardous substances in electrical and electronic equipment) has been a law in the European Union (EU). RoHS bans lead(Pb), mercury (Hg), cadmium (Cd), hexavalent chromium (Cr⁶⁺), PBBs (polybrominated biphenyls), and PBDEs (polybrominated diphenyl ethers). The implementation date is July 1, 2006. The maximum concentration value (MCV) of those six banned materials permitted in the "homogeneous materials" of an EEE has been published in the EU Official Journal and became law on August 18, 2005. It stated: "for the purposes of Article 5 (1) (a), a MCV of 0.1 % by weight in homogeneous materials for lead, mercury, hexavalent chromium, polybrominated biphenyls (PBB) and polybrominated diphenyl ethers (PBDE) and of 0.01 % by weight in homogeneous materials for cadmium shall be tolerated". There are a variety of materials used in electronic equipment which can be divided into polymers, metals,non-metals and electronic components etc.At present, there is a variety of ways to determine heavy metals. For example: Inductively Coupled Plasma Atomic Emission Spectrometry (ICP-AES), Atomic Absorption Spectrometry(AAS), Atomic Fluorescence Spectrometry (AFS) and Inductively Coupled Plasma Mass Spectrometry (ICP-MS). Compared to other techniques, the most important advantage of ICP-MS lies in its ability to measure multiple elements simultaneously. Another major advantage of ICP-MS is its high sensitivity.A method was established for the analysis of Lead (Pb),cadmium (Cd),mercury (Hg),Chromium (Cr) and Arsenic(As) in polymers by microwave digestion-Inductively Coupled Plasma Mass Spectrometry (ICP-MS) in chapter 1.The suitable sample preparation had been developed by analyzing three types of polymers,including polyethylene (PE), polyvinyl chloride (PVC), acrylonitrile butadiene styrene (ABS).The microwave digestion condition was optimized from digestion system,proportion of acids,digestion time and temperature, digestion procedures were investigated,which affords reference for the prerapation of the same kinds of polymers. To adjust the instrument operation conditions for such applications, ICP-MS instrument parameters, introduction system and stability have been optimized systematically. The proposed method was applied to the determination of Pb, Cd, Hg, Cr in different certified reference materials (CRMs), and the results obtained were in good agreement with the certified values or reference values.Method detection limits for all sample elements and the relative standard deviations (%RSD)were very low. The recoveries were between 90 %-110 %.A method was presented for the analysis of Lead (Pb) cadmium (Cd) mercury (Hg) chromium (Cr) and Arsenic (As) and other elements in metals by Inductively Coupled Plasma Mass Spectrometry (ICP-MS) in chapter 2. The available method for analyzing Lead(Pb) cadmium(Cd) mercury(Hg) chromium(Cr) and Arsenic(As) and lots of other elements accurily and rapidly had been developed by analyzing six types of metals,including ferro-alloy,tin-alloy,aluminum-alloy,copper-alloy, zinc-alloy,magnesium -alloy. The preparation of sample had been investigated,such as digestion system, proportion of acids and so on. Instrument parameters, introduction system and stability of ICP-MS have been optimized. The results for determining of Pb, Cd, Hg, Cr and some other elements in different certified reference materials (CRMs) obtained were in good agreement with the certified values or reference values. Method detection limits for all sample elements were very low, the relative standard deviations (%RSD) were almost no more than 5%, the recoveries were between 90 %-110 %. The method was developed by adding internal standardization to eliminate signal drift and matrix effects.A method was developed for the determination of Lead (Pb) ,cadmium(Cd) ,mercury (Hg) and chromium (Cr) in Non-metals. Take glass for example,the Microwave digestion condition was optimized from digestion system, proportion of acids and digestion procedure, which affords reference for the preparation of the same kinds of glass samples. Method detection limits for all sample elements were between 2.6-12 ng·g^-1, the RSDs were between 1.4-6.5 % .