7. Solving a chemistry problem

5. When determining platinum elements (Pd, Pt, Rh, Ir), after decomposition and appropriate treatment, a weighed portion of a sample weighing 1.0000 g was transferred into a solution with a volume of 10.00 ml. Samples of 100.00 μl of the resulting solution were placed in an electrothermal atomizer (graphite tube) of an automatic atomic absorption spectrophotometer, and the absorption signal of the analytical line of the element was recorded on the chart tape of the element in the form of a peak with a height hx, mm.
To construct a calibration curve, 100.00 μl of standard solutions of platinum metal salts were sequentially introduced into the atomizer and the values of h mm of the peaks were measured.
Cst(Ir), μg/ml 0.10 0.20 0.40
h (Ir), mm 12.0 24.0 48.0
Calculate the concentration of iridium in the sample (g/t)……. h=21 mm.