複選題

17. Which of the following statements correctly distinguish among the three quantification methods?
(A) The external standard method assumes that the sample matrix has no effect on the analytical signal, and uses a calibration curve generated from standards in a clean matrix.
(B) The standard addition method is best when matrix effects (biological fluid like blood serum) are suspected.
(C) The internal standard method requires that the standard be the same compound as the analyte, and requires plotting the ratio of analyte signal to internal standard signal.
(D) The internal standard method compensates for variation in sample preparation or instrument drift, which is suitable for the GC-MS method with inconsistent injection volume.

(E) The standard addition method requires a separate blank matrix for calibration and then plots signal versus added concentration to find the original concentration.