was repeated 3 times at each concentration under the conditions
described in quantitative HPLC analysisto give a 5 point calibration curve. Calibration curves with high linearity
were obtained for acTSE and acGSE by plotting the
concentrations as a function of peak areas from HPLC
analysis of a 20 L injection volume. The samples were
identified by comparing the retention time with those of
standards (acTSE and acGSE), and the concentrations of
the samples were determined from the calibration curve.