Event Title

Quantitative Determination of Acetylsalicylic Acid by Quantitative Nuclear Magnetic Resonance Technique (q-NMR)

Location

D34000

Start Date

1-4-2016 2:20 PM

End Date

1-4-2016 2:35 PM

Description

The pharmaceutical industry mainly uses chromatographic techniques, such as high performance liquid chromatography and gas chromatography, to determine the quantity of the active ingredients and other materials in the drugs. Quantitative 1H-NMR technique (q-NMR) provides an alternative rapid, selective, and accurate method for quantification of these drugs and a wide variety of other organic compounds using minimal solvent, thus making it an environment friendly technique. In this study, quantitative analysis of acetylsalicylic acid (active ingredient of aspirin) was accomplished by q-NMR technique in 300 MHz NMR instrument. Two sets of concentrations of acetaminophen in deuterated chloroform – ranging from 10 mM to 100 mM and 1 mM to 10 mM – were analyzed using tertiary-butanol as an internal standard in septuplicate to show the robustness of the method. The peak area of two regions of protons in acetylsalicylic acid – methyl group peak and aromatic ring peaks – were quantified with respect to the methyl group peak area of the internal standard, tertiary-butanol. The result showed a linear relationship of aromatic peaks with the both the low and high concentrations. The area of methyl peak of acetylsalicylic acid did not show a linear relationship at the low concentration range as the carboxylic acid proton interfered with the methyl peak at these concentrations. A conclusion is made to use aromatic protons of acetylsalicylic acid and not use methyl protons for q-NMR studies.

Comments

Dr. Shelly Kumar is a Professor of Chemistry and Mr. Charles Flemming is a graduate student in Analytical Chemistry in the College of Arts and Sciences.

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Apr 1st, 2:20 PM Apr 1st, 2:35 PM

Quantitative Determination of Acetylsalicylic Acid by Quantitative Nuclear Magnetic Resonance Technique (q-NMR)

D34000

The pharmaceutical industry mainly uses chromatographic techniques, such as high performance liquid chromatography and gas chromatography, to determine the quantity of the active ingredients and other materials in the drugs. Quantitative 1H-NMR technique (q-NMR) provides an alternative rapid, selective, and accurate method for quantification of these drugs and a wide variety of other organic compounds using minimal solvent, thus making it an environment friendly technique. In this study, quantitative analysis of acetylsalicylic acid (active ingredient of aspirin) was accomplished by q-NMR technique in 300 MHz NMR instrument. Two sets of concentrations of acetaminophen in deuterated chloroform – ranging from 10 mM to 100 mM and 1 mM to 10 mM – were analyzed using tertiary-butanol as an internal standard in septuplicate to show the robustness of the method. The peak area of two regions of protons in acetylsalicylic acid – methyl group peak and aromatic ring peaks – were quantified with respect to the methyl group peak area of the internal standard, tertiary-butanol. The result showed a linear relationship of aromatic peaks with the both the low and high concentrations. The area of methyl peak of acetylsalicylic acid did not show a linear relationship at the low concentration range as the carboxylic acid proton interfered with the methyl peak at these concentrations. A conclusion is made to use aromatic protons of acetylsalicylic acid and not use methyl protons for q-NMR studies.