NMR Spectroscopy as an Alternative Analytical Method for Biopolymers Without Chromophore: Example of Hyaluronic Acid in Dietary Supplements

Applied Magnetic Resonance, vol. 55, pp. 687–700

Abstract

Abstract To respond to the increasing demand for hyaluronic acid (HA) in dietary supplements (DSs) and nutricosmetics marketed for the treatment of osteoarthritis or moistening, it is essential to have an accurate and reliable method for its analysis in the final products. The study aimed to develop and validate alternative method for the quality control of HA in DSs using low-field (LF) and high-field (HF) nuclear magnetic resonance (NMR) spectroscopy at 80 MHz and 600 MHz, respectively. Moreover, chondroitin sulphate (CH), another active ingredient in DSs, can be simultaneously quantified. The 1H-NMR methods have been successfully validated in terms of limit of detection (LOD) and limit of quantitation (LOQ), which were found to be 0.1 mg/mL and 0.2 mg/mL (80 MHz) as well as 0.2 mg/mL and 0.6 mg/mL (600 MHz). Recovery rates were estimated to be between 92 and 120% on both spectrometers; precision including sample preparation was found to be 4.2% and 8.0% for 600 MHz and 80 MHz, respectively. Quantitative results obtained by HF and LF NMR were comparable for 16 DSs with varying matrix. HF NMR experiments at 70 ℃ serve as a simple and efficient quality control tool for HA and CH in multicomponent DSs. Benchtop NMR measurements, upon preceding acid hydrolysis, offer a cost-effective and cryogen-free alternative for analyzing DSs in the absence of CH and paramagnetic matrix components.

Authors 5

1. Fabienne Lang Aachen Faculty of Chemistry and Biotechnology

   Hochschule Bonn-Rhein-Sieg · FH Aachen

   Affiliation as printed

   Faculty of Applied Sciences, University of Applied Sciences Bonn-Rhein-Sieg, Von-Liebig-Straße 20, 53359, Rheinbach, Germany

   Faculty of Chemistry and Biotechnology, University of Applied Sciences Aachen, Heinrich-Mußmann-Straße 1, 52428, Jülich, Germany

2. Klaudia Adels Aachen Faculty of Chemistry and Biotechnology

   FH Aachen

   Affiliation as printed

   Faculty of Chemistry and Biotechnology, University of Applied Sciences Aachen, Heinrich-Mußmann-Straße 1, 52428, Jülich, Germany

3. Bernd W. K. Diehl
   Affiliation as printed

   Spectral Service AG, Emil-Hoffmann-Straße 33, 50996, Cologne, Germany

4. Margit Schulze

   University of Bonn · Hochschule Bonn-Rhein-Sieg

   Affiliation as printed

   Faculty of Agriculture, Rheinische Friedrich-Wilhelms-University Bonn, Meckenheimer Allee 174, 53115, Bonn, Germany

   Faculty of Applied Sciences, University of Applied Sciences Bonn-Rhein-Sieg, Von-Liebig-Straße 20, 53359, Rheinbach, Germany

5. Yulia Borisovna Monakhova corresponding Aachen Faculty of Chemistry and Biotechnology

   Saratov State University · FH Aachen

   Affiliation as printed

   Faculty of Chemistry and Biotechnology, University of Applied Sciences Aachen, Heinrich-Mußmann-Straße 1, 52428, Jülich, Germany

   Saratov State University, Astrakhanskaya Street 83, 410012, Saratov, Russia

   Spectral Service AG, Emil-Hoffmann-Straße 33, 50996, Cologne, Germany