Radioactive compounds, analysis purity

Selected entries from Methods in Enzymology [vol, page(s)] Types of organophosphorus inhibitors, 11,686-688 toxicity hazards, 11,688 purity and analysis, 11,688 solutions of organophosphorus compounds, 11,689 estimation of specific radioactivity of organophosphorus compounds, 11,689-690 method for estimating phosphorus content, 11,691 reactions with enzymes, 11,691 -701 [rate constants, 11,692 phosphorylation of chymotrypsin, 11, 694-696 identification of phosphoryl and phosphonyl peptides,... 

TLRC can be used for animal, human, and plant metabolism analysis radiochemical purity and stability assessment toxicology and biochemical studies and separation, detection, and quantification of separated radioactive zones of all compound classes. Traditional film autoradiography and LSC continue to be widely used, but phosphor imaging and layer scanners are being increasingly applied. The instruments for these methods are highly automated and... 

This method is particularly useful not only for micro determinations but as a standard procedure for determination of radiochemical purity. A known quantity of unlabelled substance is added to a mixture containing the labelled form of the substance. The compound is then isolated in pure form and the specific activity determined. The addition of a substantial quantity of inactive carrier facilitates the isolation and purification but the dilution cannot be continued indefinitely otherwise it would no longer be possible to make a reliable measurement of the radioactivity present in the isolated purified sample. Analysis for a specific metabolite by this method can be both sensitive and precise but presupposes that the carrier to use is known and available. 

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