60. Solving a chemistry problem

27. During GLC analysis of Aevit, a 10% oil solution of a mixture of vitamins A and E, 6 peaks were recorded on the chromatogram with the following characteristics (peak height h and its half-width a1/2 are expressed in the same units of measurement):
Peak No. 1 2 3 4 5 6
h 78 4 5 10 3 137
a1/2 2.5 4 2 2 2 2.5
Peaks 1 and 6 refer to vitamins A and E, respectively, peaks 2–5, to impurities.
Calculate by the method of internal normalization the mass fraction (in percent) of vitamins A and E, as well as the amount of impurities in the preparation, if 90% of the mass of the preparation is an oil base, and 10% of the mass is the sum of both vitamins and impurities.
Answer: vitamin A - 3.31%; vitamin E - 5.81%; the sum of impurities is 0.88%.