~Iethods for the determination of metals in organic compounds are generally described very briefly in the standard text-books of microchemical analysis. Since a considerable number of organic compounds containing a variety of metals has been synthesised, methods of analysis would seem to be of some importance and, indeed, a survey of the literature indicates that far more methods have been described than the text-book treatment would suggest.At first sight it would seem that a simple mineralisation, followed by a standard finish, would be all that is necessary; but an examination of the methods which have been applied indicates that the procedure may not necessarily be as simple as this, because certain types of compounds behave anomalously. ~or example losses by volatilisation can occur during mineralisation, or products of decomposition may be formed which can interfere with the final determination.Since the present authors were interested in the determination of a number of metals in organic compounds, a research of the literature was undertaken and the number of methods described was found to be far more extensive than had been anticipated. Accordingly, the work is now presented here as a comprehensive review of the subject.
Sodium.Taberu and Shelberg 1 found that the commonly accepted sodium sulphate (sulphated ash) method was unsatisfactory for many organic sodium salts especially barbiturates; these findings were supported by Collins 2. In the case of barbiturates, they found that if the organic matter was first removed by acidification and extraction, the sulphated