Lead, organo compounds determination

The element specificity of atomic absorption spectrometry has also been used in conjunction with gas chromatography to separate and determine organo-metallic compounds of similar chemical composition, e.g. alkyl leads in petroleum here lead is determined by AAS for each compound as it passes from the gas chromatograph.75... 

Direct determination of species. With a combination of techniques (e.g. GC and AAS) several distinct organic species can be isolated and determined, e.g. organo-lead, -mercury and -tin compounds (Chau and Wong, 1983). Also the distinction of several organic and inorganic species of As (Braman et al., 1977 Andreae, 1977) and Sb (Andreae, 1983) have been reported. 

Differences in shape lead to considerable differences in the ranges of structures adopted, and these modify the questions that computer modelling is seeking to address. Many molecular crystal structures have already been determined the Cambridge Structural Database (Allen et ai, 1991 Allen and Kennard, 1993) contains 140268 crystal structures of organic and organo-metallic compounds (April 1995 release). Various statistical analyses suggest that over 90% of these structures contain only one independent molecule in the... 

The most complicated speciation analysis is in plants and biological samples. Besides the compounds and ions already mentioned metals in living systems participate in a lot more complicated species. They may be bound to amino acids, proteins, peptides and the separation methods may influence their original distribution. For the determination of organo-arsenic, selenium, lead and tin hydride generation combined with different preconcentration steps may be used (Dedina and Tsalev, 1995). 

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