Currently, there is an initiative to establish industry-wide standards to ensure that dietary supplements are manufactured consistently.
HPLC analysis and solid-phase extraction can be used to determine the identity, purity, quality, strength, and composition of triterpene glycosides in dietary supplement formulations, according to Laura Watson, director of international marketing at Polymer Laboratories.
Nutraceuticals or phytoceuticals, natural products that are used to supplement the diet by increasing the total dietary intake of important nutrients, may include nutritional supplements such as vitamins, minerals, herbal extracts, antioxidants, amino acids, and proteins. Ephedra is a naturally occurring substance derived from the Chinese herbal Ma Huang. Its principal active ingredient is ephedrine, which, when chemically synthesized, is regulated as a drug.
The FDA has made a proposal to prohibit marketing of dietary supplements containing 8 mg or more of ephedrine per serving; therefore it is imperative to be able to determine the quantity of ephedra found in various foods and dietary supplements.
An automated solid-phase extraction method coupled with HPLC can determine the various levels of ephedra and ephedra-like compounds in dietary supplements more easily and accurately than manual solid-phase extraction, according to Joan Stevens, Ph.D., applications manager at Gilson.
Natural products are a complex matrix, such that interfering peaks may compromise the identification and quantitation of components and trace components. The automated solid phase extraction procedure removes much of the interfering matrix that would otherwise interfere with analysis at 210 nmthe necessary wavelength for detection of ephedra alkaloids.
An automated SPE system plays an integral part in the sample preparation of natural products and provides a higher extraction rate (relative recovery) than manual SPE.
Gilson products automate SPE applications from smaller sample processing to higher sample throughput. The full range of column dimensions (16 mL), including the 96-well format, is accommodated within the layout of the instruments. Graphically designed, drag-and-drop software simplifies method development, sample processing, and 21CFR Part 11 compliance, according to the company.
Gilsons SPE 215 System offers high-throughput solid-phase extraction and sample purification through 96-well extraction plates and 1- and 3-mL SPE cartridges. Positive-pressure elution is designed for precise liquid transfers.
The ASPEC XL4 uses positive pressure elution to automate solid-phase extraction for both routine and method development work. The system processes four samples in parallel and reportedly has the capability to process up to 50 samples per hour and up to 108 samples in a single batch. The ASPEC XLi offers automated sample pretreatment with on-line injection.
The SPE 215 System allows the user to automate SPE and liquid-handling applications from the initial wash to the final transfer, Robinson adds. This instrument uses positive pressure for SPE applications. In the case of the SPE 215, the positive pressure elutions are achieved via Gilsons integrated sealing foot design. The SPE 215 also has the ability to perform parallel injectionsinjecting up to 8 samples simultaneously.
Calipers AutoTrace SPE is a high-throughput workstation dedicated specifically for automating SPE, says Siira. The AutoTrace automates the cartridge conditioning, sample loading, and elution steps for large volumes aqueous solution extractions (up to 2,000 mL).
The unit can process up to six samples in parallel, automatically conditioning, washing, and eluting SPE cartridges with a choice of up to five reagents, Siira says. The unit also segregates aqueous and solvent waste using separate waste lines for efficient, cost-effective waste handling.
The RapidTrace SPE Workstation is a modular, scalable, automated, high-throughput solid-phase extraction platform, according to Siira. Utilizing 1-mL or 3-mL industry-standard SPE cartridges, the RapidTrace can process up to 100 samples in less than two hours, unattended. Each module can be loaded with 10 cartridges, and up to 10 modules can be connected together and controlled through a software package.
The RapidTrace specializes in automating low-volume solid-phase extractions. It is currently being used in a wide variety of industry applications primarily for bio-extractions, and especially within the regulated pharmaceutical, clinical, and forensic environment.