An environmental chemist working for the environmental protection agency (epa) was directed to collect razor clams from a heavily-contaminated river superfund site and analyze them for cadmium (cd2 ) content using graphite furnace atomic absorption spectrometry (gfaas). the chemist dried the clams at 95° c overnight and ground them in a scientific blender, resulting in ~ 50 g of homogenized dry weight. a representative 64.00 mg sample was taken from the ~ 50 g of dry material and dissolved in 100.00 ml of 0.1 m hcl to create a sample solution. using the method of standard additions, the chemist prepared five standard solutions in 100.00-ml volumetric flasks, each containing 5.00-ml aliquots of the sample solution. varying amounts of a 89.0 ppb (μg ·l-1) cadmium standard were added to each of the flasks, which were then brought to volume with 0.1 m hcl. the solutions were then examined for their cd2 content using gfaas, resulting in the following absorbance data.

determine the amount of cd2 per gram of dry clam. express your final result as milligrams of cd2 per gram of dry clam

sample cd2+ standard volume absorbance
5 2.50 0.119
5 0 0.08
5 5 0.163
5 7.5 0.20
5 10 0.241