Calibration by NMR for quantitative analysis: p-toluenesulfonic acid as a reference substance.
We have demonstrated the usefulness of p-toluenesulfonic acid (TsOH) as a reference substance to calibrate a water-soluble standard by NMR for quantitative analysis. In order to make TsOH convenient for this purpose, we first of all established its molar extinction coefficient under these conditions (epsilon = 351 at 262 nm). This was done by comparing it by quantitative NMR (qNMR) with a compound of known molar extinction coefficient, guanosine monophosphate. TsOH was then used as the standard in a second qNMR experiment to measure an aqueous solution of phosphoglycolate, a metabolite of interest in our laboratory. Perhaps due to its content of water, the purity of this compound was found to be 82%, lower than the value of 94% from the manufacturer.
Shao
Gang
G
Department of Pharmaceutical Sciences in the Bouve College of Health Sciences, Barnett Institute, Northeastern University, Boston, MA 02115, USA.
Kautz
Roger
R
Peng
Shiqi
S
Cui
Guohui
G
Giese
Roger W
RW
D001557:Benzenesulfonates / Q000032:analysis / Q000592:standards*; D002138:Calibration; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D012015:Reference Standards; D015203:Reproducibility of Results
D001557:Benzenesulfonates; C029501:4-toluenesulfonic acid