33. Solution to Chemistry Problem

41. The "standard addition method" was used to determine the lead content in a biological sample. For analysis, 50 cm3 of the test solution was taken and transferred to two separatory funnels. 0.5 cm3 of a standard lead solution with a concentration of 60 mg/dm3 was added to one of them. Lead was determined by the extraction method with diethylammonium diethyldithiocarbamate in chloroform. The lead content in the organic phase was determined by the atomic absorption method with an emission line at 283.3 nm. Determine the concentration (mg/dm3) of lead in the analyzed sample if the absorption of the lead extract in the analyzed solution and in the solution with the addition of the standard lead solution are 0.300 and 0.620, respectively.