Margit Geissler

Articles by Margit Geissler

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Contamination of public buildings with PCBs used as softeners in the 1970's in sealants and wall and ceiling paints can still be detected. If certain threshold values in indoor air are exceeded the source has to be decontaminated. This requires an effective and fast determination of the PCB concentration in indoor air. Thermodesorption GC–MS is a method especially suitable for this purpose. Polychlorinated Biphenyls (PCBs) are highly toxic and carcinogenic chemical substances. Although first prepared in 1864, they have been industrially manufactured since 1929. The highest production amounts worldwide were recorded in the 1960s and the beginning of the 1970s. In the 1970s their use as additives for building materials was widespread because of their flame inhibiting and noise reduction properties.

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Size-exclusion chromatography (SEC) and pyrolysis-gas chromatography (Py-GC) are commonly used to characterize copolymers. SEC is a powerful method to determine the molecular-weight distribution of polymers whereas Py-GC provides valuable information on their chemical composition. The combination of these two techniques could yield combined size and composition information for copolymers or polymer mixtures. A fully automated system was constructed to perform these two-dimensional (2D) characterizations. Several examples of the use of this new technique to comprehensively characterize polymers are described.

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On 13 February 2003 the European Union published the new regulation on electric and electronic waste, (WEEE, Waste Electrical and Electronic Equipment) as well as the restriction of the use of certain hazardous substances in electric and electronic equipment (RoHS). Thus both regulations became effective, and in January 2005 they were transferred into national law. According to RoHS, lead, mercury, cadmium, chromium (VI), polybrominated biphenyls (PBB) and polybrominated diphenylethers (PBDE) are forbidden from July 2006. Shimadzu, one of the leading manufacturers of analytical instrumentation offers the complete hardware and software for the secure identification of hazardous substances as well the know-how and competence.