145. Solving a chemistry problem

65. When determining lead in a biological object by the method of comparison, 100.00 ml samples were taken, diluted 5 times and 25.00 ml of this solution was taken for analysis. Lead was extracted with methyl amino ketone (10.00 ml) using diethyldithiocarbamite. 10.00 ml of a standard lead solution with a concentration of 0.4000 μg PB in 1.0 m was used as a reference solution. Extraction of lead was carried out similarly. The atomic adsorption of the extracts of the analyzed and standard solutions at 283.3 nm is 0.240 and 0.320. Determine the concentration (mg / l) of lead in the analyzed solution.