Determining percent purity using Quantitative Proton NMR (qHNMR/qNMR)

qNMR (quantitative NMR) or qHNMR (quantitative proton NMR) can be used as a purity assay to assess the percent purity of an NMR sample.

This video provides an overview using the 4 different qHNMR methods to determine percent purity of an NMR sample. Knowing the percent purity is useful for measuring how much of a final product is pure. Conversely, the percent purity can determine the amount of impurity present in a final product.

I decided to make a video about qHNMR because I could not find any videos covering the 4 methods anywhere on YouTube or Google. A previous video I made utilized the 100% method. Although I gave a lengthy overview of the method, I felt I did not give it my best explanation, as it may have left many confused (link to the video: Synthesis of Virstatin and Purity Ana...).

So to enhance that video and give the 100% method proper justice, I wanted to make this video as reference for those who are confused or have trouble finding the correct values for the formulas in each of the 4 methods.

Yes, it is a loooong video (originally, it was over 1 hour before I did the editing) but here are some timestamps:

100% Method (6:08)
Internal Calibrant Method (19:08)
External Calibrant Method (24:33)
ECIC Method (28:58)

• #education
• #qhnmr
• #quantitative
• #proton
• #nmr
• #nmr
• #purity
• #assay
• #qnmr