Brannon and Patrick give details of studies on the distribution and mobility of antimony in sediments from several sites in rivers, waterways and coastal waters throughout the USA. Most of the naturally-occurring and added antimony in the sediments was associated with relatively immobile iron and aluminium compounds. A direct spectrophotometric procedure has been described for the determination of parts per billion of hydrochloric acid releasable arsenic in river sediments. Hydride generation inductively coupled plasma atomic emission spectrometry has been used to determine arsenic in non-saline sediments. Cutter has described a selective hydride generation technique as the basis for the differential determination of total arsenic in oxidatively digested river sediments. A three-step sequential extraction scheme has been proposed for extracting chromium from sediments. This scheme employs acetic acid, hydroxylamine hydrochloride and ammonium acetate as extracting agents. A gold coated graphite furnace atomic absorption spectrometer has been used to determine mercury in non-saline sediments.