0731. Solving a chemistry problem

47. To control the formaldehyde content in the air, 10,000 liters of air were passed through 1 liter. absorber with a recovery rate of 80%. A sample with a volume of 1 μl was taken from the resulting solution and introduced into the chromatograph. A formaldehyde peak with an area of 234 mm2 was detected. The formaldehyde calibration curve was constructed from standard solutions with concentrations of 0.1, 0.2, 0.3, 0.4 and 0.5 mg/L, with an injected sample volume of 0.1 μL. The areas of their peaks will be 13, 27, 38, 50 and 67 mm2, respectively. Determine the content of formaldehyde in the air.