90. Solving a chemistry problem

15. Trichloroacetic acid (TCA) is quantitatively extracted with a solution of methyldioctylamine (MDOA) in chloroform. From 400 mg of the herbicide, with a mass fraction of TCA of 72%, the latter was quantitatively extracted with 10 ml of a solution of MDOA in chloroform, and with chromatography of 10 μl of the extractant, a peak of STCU = 72 mm2 was obtained. What weighed amount of TCA should be taken to prepare 25 ml of a standard solution in order to obtain a peak of STCU = 100 mm2 during chromatography under the same conditions?