Transalkylation reactions of mercury species during sample preparation and storage.
Examwork in Analytical Atomic Spectrometry
James Snell, Magnus Johansson and Wolfgang Frech
Avdelningen f÷r Analytisk Kemi, Umeň Universitet, 901 87 Umeň.
At present, methods of mercury species separation are available to convert the different mercury salts present in a sample to non-polar derivatives, thereby improving their chromatographic properties. Conversion methods may involve Grignard reagents, alkylboranes or iodides. It is desirable that the original chemical forms present in the sample are not changed during conversion reactions, except for the addition of the desired group or groups. Unfortunately, the integrity of various forms of mercury, present in the original sample, can not be taken for granted. Transalkylation reactions have in fact been observed during derivatisation, leading to systematic errors in analytical results. Similar reactions may as well take place during sample storage as a result of transalkylation reactions involving other organometal species present. In natural samples, such organometal species are always present and also the risk to disturbe the species distribution.
This project has two aims. Firstly, you will determine the reactions taking place during sample preparation (derivatisation with Grignard reagents) and evaluate the suitability of some selected preparation methods for speciation studies. Secondly, you will study the stability of mercury species in natural samples, in the presence of other organic metal compounds.
For more detailed information please contact:
Uppgiften inf÷rd 3 december, 1996 av firstname.lastname@example.org alias
Magnus Johansson, Avdelningen f÷r Analytisk Kemi, Umeň Universitet, 901 87 Umeň.