The dissolved mercury is then reduced with a stannous chloride solution and removed from the solution in a stream of nitrogen. The arrangement for the cold-vapor AAS instrument is shown in figure 14 . Individual apparatus and equipment items are listed here. One-way check valves. Three-way stopcocks, borosilicate glass.
All chemical reagents are of reagent-grade or higher purity.
Doubly-distilled water is used in the preparation of all solutions. Mercury metal, high purity. SnCl 2 . Nitrogen gas, 99-percent pure. This solution should be freshly prepared each month.