Abstract: An apparatus and method for atomic absorption spectrophotometric measurement of submicrogram amounts of mercury utilizing a combined absorption-reduction cell sized to fit within the absorption compartment of a standard spectrophotometer. The absorption-reduction cell comprises an absorption chamber which is generally cylindrical in shape and a mixing chamber connected to the lower portion of the absorption chamber into which the sample to be analyzed and a reductant are added. The cell also includes an inlet port, and outlet port, and an air intake port used to flush and clean the cell after use.