1, and the ordinate is the area ratio of chromatographic peaks. Because the internal standard is the same as the standard, a regression equation is obtained by linear regression analysis of the concentration ratio of several injections and the corresponding peak area ratio. Then, when the sample is determined, the same internal standard is added to the sample, and the peak area of the chromatographic peak is obtained after the sample is injected. The sample with unknown concentration ratio and the measured peak area are brought into the regression equation, and the concentration of the measured sample can be obtained.
Both statements are correct. The abscissa of the internal standard curve of the internal standard method is the same as the abscissa, but the expression is different and can be converted, but it is generally expressed by mass concentration in application.