Asset Publisher

New qNMR internal standard for pharmaceuticals and other organofluorine compounds

Organofluorine compounds represent an important class of pharmaceuticals, about 20% of which are fluorinated compounds. Other application areas for organofluorides are agriculture, cosmetics, biomolecule analysis and functionalized materials. Their production requires rigorous manufacturing processes and purity characterization. Accurate purity assignment can be performed using Fluorine-19 quantitative nuclear magnetic resonance (19F qNMR) with appropriate internal standards and experimental methods.

The internal standard reference document was published by the BIPM in collaboration with seconded experts from INMETRO (Brazil), BAM (Germany), INTI (Argentina) and NMIJ (Japan). The project was established to enable the application of fluorine based qNMR methods for rapid, SI-traceable purity assignment, and provide an alternative to the application of proton based methods where overlapping signals can limit the application of the technique.

BIPM report

This publication describes how 3,5-Bis(trifluoromethyl) benzoic acid can be used as an internal standard for measurements of purity of fluorinated compounds with qNMR. It complements the currently available “qNMR octad” of internal standards, which describes a suite of eight reference materials that can be used for 1H qNMR purity determination of organics.

Further information is available here .