Calibration data were determined for all the analytes under
investigation, using the chromatographic and derivatization conditions
described in Section 2.6 and 2.7. The calibration curves were
generated by carrying out a series of separations of standard mixtures
containing the ITCs within the ranges of 0.005–0.1 lmol/mL
and 0.1–1.0 lmol/mL after pre-column derivatization. Three independent
measurements were carried out for each calibration point.
Calibration lines based on six calibration points were prepared by
plotting concentration versus chromatographic peak area of the
analyte and applying the least squares method. The results of