5. Solving a chemistry problem

43. 1. To determine the content of ethmozine and ethacizine in the tablets of the metacysin preparation by HPLC, 0.06 g of the powder of crushed tablets is placed in a 25 ml volumetric flask, 20 ml of a 0.02 mol / l solution of potassium dihydrogen phosphate is added, the mixture is thoroughly mixed, the volume is adjusted solution in the flask with the same solvent up to the mark, mix and filter. 2 ml of the filtrate is taken, transferred to a 25 ml volumetric flask, the volume of the solution is adjusted to the mark of 0.02 mol/l with a solution of potassium dihydrogen phosphate, stirred and the test solution is obtained, which is subjected to chromatography on an HPLC chromatograph.
Under the same conditions, a standard solution containing ethmosine and etacizine with a concentration of 0.000096 g/ml and 0.000017 g/ml, respectively, is chromatographed.
Derive the following formula to calculate the X content of ethmozine or ethacizine in one tablet in grams:
X \u003d S (X) s (st) * 25 * 25 * v / 2S (st) a
where S(X) and S(st) are the peak area on the chromatogram of the test and standard solution, respectively; c(st) is the concentration of etmosin or ethacizin in the standard solution, g/ml; a - weighed powder of crushed tablets, g; c – average weight of one tablet, g.