By Joseph Zhou, Ph.D., Director of Laboratory Methods and Scientific Support [retired], NOW Foods
The AOAC Methods Committee on Dietary Supplements in April voted unanimously to approve NOW Foods’ method, Determination of Glucosamine in Raw Materials and Dietary Supplements Containing Glucosamine Sulfate and/or Glucosamine Hydrochloride by HPLC with FMOC-Su Derivatization, as an AOAC First Action Official Method SM.1 This method has been designated as AOAC method 2005.01, and will be published in the July/August 2005 issue of the Journal of AOAC INTERNATIONAL.
AOAC INTERNATIONAL is a 120 year-old not-for-profit scientific association committed to worldwide confidence in analytical testing results. The organization was formerly known as the Association of Official Analytical Chemists. The AOAC Official Method Program is the result of a contract between the Center for Food Safety and Applied Nutrition, the FDA and the Office of Dietary Supplements, part of the National Institutes of Health, with AOAC INTERNATIONAL. The purpose of the contract is to provide the FDA, other government agencies, and the dietary supplements industry with AOAC Official Methods suitable for testing both raw materials and commercially available dietary supplements.
In April 2003, AOAC’s Expert Review Panel (ERP) on glucosamine selected NOW’s glucosamine method as the best method for further laboratory validation. Since then, the method has successfully completed AOAC’s rigorous validation process, which includes both single laboratory validation and collaborative study. Twelve validation laboratories worldwide, ten in the United States, one in Canada and one in Germany, participated in the collaborative study. The method is simple, robust and accurate.2,3
Five types of test materials were included in the collaborative study: (1) tablets, (2) capsules, (3) drink mix powders, (4) raw materials, and (5) liquid products. The materials selected included glucosamine from shellfish and vegetarian sources, in both the hydrochloride and sulfate salt forms, as well as glucosamine in combination with other ingredients commonly found to co-occur in dietary supplement formulas - including MSM, SAMe, chondroitin sulfates and Vitamin C - at levels commonly found in commercially available products. It is believed that the method may easily be extended to products not covered by the collaborative study through AOAC’s new mechanism for matrix extension of its Official Methods SM. None of the results from the collaborating laboratories was an “outlier” (test results out of the expected range), indicating the robustness and accuracy of the method.
We first developed this glucosamine method in the NOW lab five years ago and have been using the same method for our quality control of glucosamine products ever since then. This is now becoming the only internationally accepted standard method for testing glucosamine products. NOW’s accomplishment in developing this glucosamine method evidences our high standards in quality testing to assure product quality, as well as providing a significant contribution to an industry advancement of scientific methods. We employ one of the finest teams of product quality experts in the supplement industry and conduct specialized tests, analyses and inspections that allow our company to offer superior products to our customers.
1 The AOAC INTERNATIONAL publication, Inside Laboratory Management, July/August 2005, Page 5
2 J. Zhou, T. Waszkuc, F. Mohammed. Single Laboratory Validation of a Method for Determination of Glucosamine in Raw Materials and Dietary Supplements Containing Glucosamine Sulfate and/or Glucosamine Hydrochloride by High Performance Liquid Chromatography with FMOC-Su Derivatization. Journal of AOAC INTERNATIONAL, Vol. 87, No. 5, 2004, Pages 1083-1092
3 J. Zhou, T. Waszkuc, F. Mohammed, C. Ray, R. Buren, W. Wang, H.Nguyen, J. Jabusch, D. Sullivan, X. Kou, Q. Yang, A. Solyom, J. Wang, T. Peng, Q. Zheng, M. Blumhorst, M. Nagarajan, B. Podhola, L. Huang, C. Shevchuk, R. Das, K. Orellana, K. Reif. Determination of Glucosamine in Raw Materials and Dietary Supplements Containing Glucosamine Sulfate and/or Glucosamine Hydrochloride by High Performance Liquid Chromatography with FMOC-Su Derivatization: Collaborative Study. Will be published in Journal of AOAC INTERNATIONAL, July/August, 2005