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Badania polimorfizmu związków bioorganicznych metodami spektroskopii NMR w fazie stałej

Kaźmierski S., Potrzebowski M.J.

Wiadomości Chemiczne

2006

[Z] 60, 11-12

723-745

Polymorphism is one of the most important and amazing phenomenon in structural chemistry. The knowledge of this phenomenon is crucial both in experimental sciences (e.g.: chemistry, physics and crystallography) and in industry - especially in pharmaceutical industry. It is well known, that polymorphic forms of therapeutic compounds differ in their bioavailability - e.g. the rate of dissolution and equilibrium solubility. In extreme cases, one polymorph may be a medicine whilst the second may be very dangerous or even poisonous. In this light, the possibility to distinguish the desirable form of compound from the useless form, seems to be very important. In our article, some problems concerning the investigation of polymorphism phenomenon by applications of solid-state NMR are presented. The possibilities of current NMR techniques in searching of polymorphism as well as the practical aspects and applications are presented and discussed.

Sea surface microlayer: a field evaluation of teflon plate, glass plate and screen sampling techniques. Part 2. Dissolved and suspended matter

Falkowska L.

Oceanologia

1999

No. 41 (2)

223-240

The similarities and differences in chemical composition of particular sub-layers of the sea microlayer are discussed on the basis of data obtained from the open sea region of the Gdansk Basin. Three methods of microlayer sampling were tested simultaneously, resulting in sub-samples of different mean thickness (10, 90, 250 žm). Samples were analysed to determine dissolved NO3-, NH4+, PO43-, Ptot and DOC, as well as suspended components (chl a, phae a, ATP, POC, particle size distribution and algae). It was found that the stratified microlayer forms a medium extremely diversified chemically and biologically. Variable ranges of concentration as well as varying frequencies of the depletion or enrichment coefficient in each measurement period indicate disparate conditions in the microlayers, which are related to the intensity of primary production and the destruction of organic matter. Comparative studies provided no evidence for the preferential application of any of the sampling techniques to obtain the most accurate picture of dissolved organic and inorganic substances in the sea surface microlayer. In the case of particulate organic matter, satisfactory results were obtained with the classic screen technique. The article highlights the merit of simultaneous studies by various sampling techniques in answering questions related to the sea surface microstructure and the momentum of photochemical and biological processes at its different levels