A cold vapour technique for the determination of mercury in geological materials involving its reduction with tin(II) chloride and collection on gold wire

Abstract

A technique for the determination of mercury in geological materials is described in which mercury liberated from the sample by tin(II) chloride is collected on gold-wire clippings and determined by flameless atomic absorption after heating the gold in an easily constructed resistance furnace. During the heating stage the stream of air used to carry the atomic mercury vapour is diverted through a by-pass. The method gives a five-fold increase in sensitivity over reduction with tin(II) chloride alone and is free from non-atomic-absorption interferences when single-beam detectors are used. The detection limit is 0·001 µg of mercury and the coefficient of variation for 0·080 µg of mercury is 3·9 per cent.