The application of the oxygen-flask combustion technique to the determination of trace amounts of chlorine and sulphur in organic compounds

Abstract

The Schöniger oxygen-flask technique has been adapted to trace analysis. An electrically fired apparatus has been designed that is capable of combusting up to 100 mg of material. As little as 0·1 µg of chloride can be titrated potentiometrically with silver nitrate solution.

Sulphate is titrated with barium perchlorate with thorin as indicator. Visual and spectrophotometric detection of the end-point has been investigated and the latter is preferred for amounts down to 0·5 µg of sulphate. Cations which interfere can be readily removed by ion exchange.