Precolumn Derivatization Liquid Chromatography Method for Analysis of Dietary Supplements for Glucosamine: Single Laboratory Validation Study
Abstract:A precolumn derivatization liquid chromatography (LC) method was developed for the analysis of various dietary supplement formulations and raw materials for glucosamine. A 1 mL sample or standard water solution (containing about 0.05 mg glucosamine) was mixed with 1 mL pH 8.3 buffer, 1 mL 5% phenylisothiocyanate methanolic solution, and derivatized at 80°C in a water bath for 30 min. After derivatization, the solution was cooled in a cold water bath and centrifuged at 3000–5000 rpm. The clear upper layer was ready for injection. The LC system was equipped with a C18 reversed-phase column and an ultraviolet detector set at 240 nm. The column was developed with a linear gradient composed of 0.1% phosphoric acid in deionized water and 0.1% phosphoric acid in methanol. The method was subjected to Single Laboratory Validation. The method precision was 0.50% relative standard deviation, accuracy was less than ±1.5%, method linearity in the range 0–2 mg glucosamine/mL was 1.00, the detection limit was 0.0705 μg/mL, and the quantitation limit was 0.235 μg/mL. Chondroitin sulfate, amino acids, and excipients did not interfere with glucosamine testing. After derivatization, both standard and sample preparations were stable for at least 48 h. Due to its high sensitivity, this method can be used to assay glucosamine in functional foods and pet foods. The validation data will be published separately.
Document Type: Research Article
Affiliations: Analytical Laboratories in Anaheim, Inc., 1241 N. Lakeview Ave, Suite Q, Anaheim, CA 92807.
Publication date: March 1, 2005
More about this publication?
- The Journal of AOAC INTERNATIONAL publishes refereed papers and reviews in the fields of chemical, biological and toxicological analytical chemistry for the purpose of showcasing the most precise, accurate and sensitive methods for analysis of foods, food additives, supplements and contaminants, cosmetics, drugs, toxins, hazardous substances, pesticides, feeds, fertilizers and the environment available at that point in time. The scope of the Journal includes unpublished original research describing new analytical methods, techniques and applications; improved approaches to sampling, both in the field and the laboratory; better methods of preparing samples for analysis; collaborative studies substantiating the performance of a given method; statistical techniques for evaluating data. The Journal will also publish other articles of general interest to its audience, e.g., technical communications; cautionary notes; comments on techniques, apparatus, and reagents.
- Information for Authors
- Submit a Paper
- Subscribe to this Title
- Information for Advertisers
- Journal Information
- Ingenta Connect is not responsible for the content or availability of external websites