The determination of tin and antimony in lead alloy for cable sheathing by atomic-absorption spectroscopy

Abstract

A method has been evolved for the rapid determination of tin and antimony at levels of about 0·4 and about 0·2 per cent., respectively, in lead alloy used for sheathing electric cables.

The sample is dissolved in a mixture of fluoroboric acid and hydrogen peroxide and the determination is completed by atomic-absorption spectroscopy with the use of an air-acetylene flame for antimony and a nitrous oxide-acetylene flame for tin. The method of dissolving the sample avoids the precipitation reactions that are likely to arise from lead, antimony or tin if conventional acid dissolution processes are used and hence permits a direct and rapid analysis by the atomic-absorption technique.

Calibration for antimony must be effected with a solution containing the dissolution mixture and, in calibration for tin, lead must additionally be present.