19. Solving a chemistry problem

192. A portion of a sample containing iron, after decomposition and appropriate processing, was transferred to a solution of 50 ml; then, 5 ml aliquots of the resulting solution were introduced into two 50 ml volumetric flasks, and 100 µg of the iron standard solution was added to one of them. Got atomic steam. The optical density at a wavelength of the iron line λ = 227.9 nm for the analyzed solution and the analyzed solution with the addition of a standard solution was 0.45 and 0.85, respectively. Determine the mass of iron in the sample in grams.