ORCID
- Julie Dunne: 0000-0002-5858-2694
Abstract
Two new analytical methods, applying absolute 1H qNMR, were developed to monitor product yield and quantify unreacted carbohydrate and fatty acid reactants, in the synthesis of carbohydrate fatty acid esters (CFAE). These methods provide a mass balance of the crude reaction mixtures and diversify the analytical screening and quantitation approaches available within the synthesis of these molecules. Both methods were validated for the model reaction of methyl α-d-glucopyranoside (MAG) and lauric acid (LA) to form the mono ester product, methyl 6-O-dodecanoyl-α-d-glucopyranoside. Analysis in CD3OD by 1H qNMR, with fumaric acid (FA) as an internal standard (IS), allowed monitoring of all reaction components. Alternatively, using CDCl3 and (E)-stilbene as IS enabled the analysis of CFAE and fatty acid. Parameters calculated for method validation included specificity and selectivity, linearity, accuracy, intermediate precision, limit of detection (LOD), limit of quantification (LOQ) and robustness. Both methods provided excellent linearity with R2 > 0.997. The accuracy, precision, and robustness of the method in CD3OD was <2 % uncertainty making it suitable for complete reaction analysis. The method completed in CDCl3 resulted in accuracy, intermediate precision, and robustness of <5 %, except for accuracy in the lowest levels of concentration (>5 %). For all related analytes in the CD3OD and CDCl3 methods, the LOD and LOQ were determined to ensure applicability for the intended use in the assessment of reaction crude composition. Finally, the system suitability was assessed in a scaled lipase catalysed CFAE synthetic reaction. The determined qNMR product yields were verified against isolated purified product yields with <5 % uncertainty.
Keywords
% yield determination, Carbohydrate fatty acid esters, Internal standard, Quantitative H NMR
DOI Link
Publication Date
2024-06-03
Publication Title
Carbohydrate Research
Volume
540
ISSN
0008-6215
Deposit Date
2025-07-18
Funding
The authors thank the South East Technological University PhD Scholarship Programme (WD_2020_60_WSCH) for the funding of this project. The authors wish to thank Dr Adolfo Botana from JEOL UK for NMR technical assistance with the JEOL ECX 400 MHz instrument, qNMR experimental parameters and DELTA software and Dr Sean Roche for NMR support within the PMBRC.
Creative Commons License
This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License
Additional Links
Recommended Citation
Rayak, Abinash; Dunne, Julie; Kinsella, Michael; and Lennon, Claire M., "Development of a rapid quantitative method of analysis of carbohydrate fatty acid ester reaction mixtures using 1H qNMR" (2024). Research Outputs: 2025-Present. 32.
https://arrow.tudublin.ie/schfsehro/32