Graduation thesis can't reach three nines on the standard curve. N groups of standard solutions with different mass fractions can be prepared with pure substances and diluents of predicted components, and then each group is measured, and then the standard curve of response signal (ordinate) versus mass fraction (abscissa) is drawn, which is a curve passing through the origin. Do a set of meteorology for the measured element to get the response signal of the mode. (Find the value of the response abscissa from the value of this ordinate) Secondly, you should improve your requirements, do analytical experiments, strive for perfection, and not be careless.