ABP Operating Guidelines  – Version 9.0 – July 2023  Page 51/91 Completeness of the derivatization shall be controlled in each Aliquot  through  the monitoring of mono- O-TMS vs. di -O-TMS derivative of A.  T/E Ratio  The T/E ratios shall be determined from the ratios of chromatographic peak areas or peak heights after correction against a calibrator or a calibration curve.