An environmental chemist working for the EnvironmentalProtection Agency (EPA) was directed to collect razor clams from aheavily-contaminated river superfund site and analyze them forcadmium (Cd2 ) content using graphite furnace atomic absorptionspectrometry (GFAAS). The chemist dried the clams at 95° Covernight and ground them in a scientific blender, resulting in ~50 g of homogenized dry weight. A representative 64.00 mg samplewas taken from the ~ 50 g of dry material and dissolved in 100.00mL of 0.1 M HCl to create a sample solution. Using the method ofstandard additions, the chemist prepared five standard solutions in100.00-mL volumetric flasks, each containing 5.00-mL aliquots ofthe sample solution. Varying amounts of a 89.0 ppb (μg ·L-1)cadmium standard were added to each of the flasks, which were thenbrought to volume with 0.1 M HCl. The solutions were then examinedfor their Cd2 content using GFAAS, resulting in the followingabsorbance data.
Determine the amount of Cd2 per gram of dry clam. Express yourfinal result as milligrams of Cd2 per gram of dry clam
| Sample 5 | cd2+ standard volume 0 | absorbance 0.080 | |
| 5 | 2.50 | 0.119 |
| 5 | 5 | 0.163 |
| 5 | 7.50 | 0.200 |
| 5 | 10 | 0.241 |
| | | |
