Abstract A flow-injection, cold-vapor atomic absorption spectrophotometric method was developed for the determination of trace amounts of mercury in a proposed zinc ore concentrate Standard Reference Material (SRM 113b). The samples were digested with nitric and hydrochloric acids in closed Teflon digestion vessels. The experimental details for sample preparation and the flow injection method are discussed. The effect of matrix and various acid concentrations on the extraction and subsequent analysis of mercury were also studied. The method has a detection limit of 0.08 μg Hg/g in the sample. A certified reference material (CZN-1) was analyzed and the results obtained agreed well with the certified value.