1 research outputs found
Practical and Economical Implementation of Online H/D Exchange in LC-MS
Structural elucidation is an integral
part of drug discovery and
development. In recent years, due to acceleration of the drug discovery
and development process, there is a significant need for highly efficient
methodologies for structural elucidation. In this work, we devised
and standardized a simple and economical online hydrogen–deuterium
exchange methodology, which can be used for structure elucidation
purposes.Deuterium oxide (D<sub>2</sub>O) was infused as a
postcolumn addition
using the syringe pump at the time of elution of the analyte. The
obtained hydrogen/deuterium (H/D) exchange spectrum of the unknown
analyte was compared with the nonexchanged spectrum, and the extent
of deuterium incorporation was delineated by using an algorithm to
deconvolute partial H/D exchange, which confirmed the number of labile
hydrogen(s) in the analyte. The procedure was standardized by optimizing
flow rates of LC output, D<sub>2</sub>O infusion, sheath gas, and
auxiliary gas using the model compound sulfasalazine. The robustness
of the methodology was demonstrated by performing sensitivity analysis
of various parameters such as concentrations of analyte, effect of
matrices, concentrations of aqueous mobile phase, and types of LC
modifiers. The optimized technique was also applied to chemically
diverse analytes and tested on various mass spectrometers. Moreover,
utility of the technique was demonstrated in the areas of impurity
profiling and metabolite identification, taking pravastatin-lactone
and N-oxide desloratidine, as examples