Routine Analysis of Mercury. A comparative Study between two Methods; neutron activation and flameless atomic absorption

Abstract

Mercury analysis was performed on purely routine basis om samples of organic origin. The object was to compare the two analytical methods at IVL, neutron activation and flaemless atomic absorption, both available as a routine service. The investigation was based on eight samples, run a striplets, showed: Neutron activation has an excellent accuracy with a coefficient of variation of less than 5 % when mercury level exceeds 2 ppb (ng/g). All of the performed analyses gave good results. - Flameless atomic adsorption samples were digested in either of three media: aqua regia (inorganic matter), sulfuric, nitric an dperchloric acid or dulfuric and nitric acids combined with permangante and persulfate. Two performance with aqua regia was acceptable while no agreement was obtianed with the two other methods Loss of mercury occured compared to the reference values. Digestion with permanganate and persulfate showed the best agreement. The maximun loss was 35 %. Moreover detection limit was high because of the high background. At best is was found to be 5 ppb (ng/g). The comparative study gives neutron activation a very strong hand.Mercury analysis was performed on purely routine basis om samples of organic origin. The object was to compare the two analytical methods at IVL, neutron activation and flaemless atomic absorption, both available as a routine service. The investigation was based on eight samples, run a striplets, showed: Neutron activation has an excellent accuracy with a coefficient of variation of less than 5 % when mercury level exceeds 2 ppb (ng/g). All of the performed analyses gave good results. - Flameless atomic adsorption samples were digested in either of three media: aqua regia (inorganic matter), sulfuric, nitric an dperchloric acid or dulfuric and nitric acids combined with permangante and persulfate. Two performance with aqua regia was acceptable while no agreement was obtianed with the two other methods Loss of mercury occured compared to the reference values. Digestion with permanganate and persulfate showed the best agreement. The maximun loss was 35 %. Moreover detection limit was high because of the high background. At best is was found to be 5 ppb (ng/g). The comparative study gives neutron activation a very strong hand