Continuing our series of blog posts on analytical solutions for the determination of vitamins in nutritional supplements and functional waters to ensure product quality and regulatory compliance(US FDA dietary supplement regulatory information) as well as to monitor vitamin intake. In case you have not as yet read the first post released earlier this week, I do encourage you to check it out as it includes links to two downloadable application notes. As mentioned in that first post, the market for both these areas continues to grow rapidly around the globe. Even though the United States continues to be the largest market for nutritional and dietary supplements (Business Wire story on a comprehensive report), according to this story, the nutritional supplement market in India is expected to double by 2013. (In case you are interested, the story also provides an overview of the regulatory situation in India for nutritional supplements.)
Here we feature an application note and a poster note on testing vitamins in beverages and other matrices.
Vitamin B12 in Beverages Using Online SPE for HPLC Analysis with UV Detection
While reversed-phase HPLC with fluorescence, mass spectrometry (MS), or UV detection are good techniques for Vitamin B12 determination in food, the strategy is not always suitable for its determination in beverages. Vitamin B12 in beverages is often too diluted to detect, and direct large-volume injection, if possible, introduces interfering compounds. Therefore, Vitamin B12 analysis usually involves complicated sample preparation, which presents challenges for product quality control. Application Note 256, Determination of Vitamin B12 in Beverages Using On-Line SPE Followed by HPLC with UV Detection, (downloadable PDF) describes a simple, fast, and effective online method using solid-phase extraction (SPE) on reversed-phase cartridges to concentrate the analyte from liquid samples and eliminate most of the interfering compounds for subsequent HPLC analysis with UV detection.
Sensitive, Selective Measurement of Fat-Soluble Vitamins (FSVs) and Antioxidants (FSAs)
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Even though many FSVs and FSAs are measured by HPLC-UV, this approach typically lacks the sensitivity and selectivity required to measure these compounds in biological samples. Electrochemical detection, however, is both sensitive and selective and makes use of the inherent redox activity of these compounds. The Thermo Scientific Dionex CoulArray* Coulometric Array Detector—the only HPLC electrochemical detector that is fully gradient compatible—uses an array of flow-through, highly efficient electrochemical sensors to generate qualitative voltammetric data to help identify analytes resolve coeluting compounds. This poster, titled,Analysis of Fat-Soluble Vitamins and Antioxidants in Supplements by RP-HPLC, (downloadable PDF) demonstrates five examples:
- Global gradient method for determination of FSVs and FSAs in plasma
- Gradient method for the analysis of carotenoid isomers in carrots and human plasma
- Isocratic method for the measurement of reactive nitrogen species damage to biomembranes measuring 5-nitro-gtocopherol in rat astrocytes
- Gradient method for the measurement of tocopherol and tocotrienol isomers in palm oil
- Isocratic method for the determination reduced and oxidized CoQ9 and CoQ10 in human plasma
Next blog post on measurement of fat-soluble vitamins and antioxidants, and separation of water and fat soluble vitamins in a single analysis, and separation of Vitamin K isomers!
In case you are interested in testing for other compounds in nutritional supplements, visit our website for analytical applications for a range of dietary and herbal supplements.
Also, don’t hesitate to comment below if you would like more details or found this information useful. We look forward to hearing from you!