Page 79 - Instrumental Analysis - Pharm D Clinical- 07-PA403
P. 79
Internal standard method
To overcome the variation in chromatographic conditions (i.e.
flow rate, pressure, etc.) between runs
● The internal standard must
1- be similar in structure to the sample component
2- not overlap with the sample component peak
● The internal standard solution is added to each standard
solution (to construct the calibration graph) and to the sample
● A calibration curve is prepared by plotting
the standard/internal standard peak area ratio (Y-axis) versus
the concentration of the standard (X-axis).
Prof. Omayma Abdelrazak Amin 67
67
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Prof. Omayma Abdelrazak Amin 68
68
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