Solid phase extraction system for vitamin D and its major metabolites in human plasma

Area of Science:

• Analytical Chemistry
• Biochemistry
• Clinical Chemistry

Background:

• Accurate quantification of vitamin D and its metabolites in plasma is crucial for clinical diagnosis and research.
• Conventional extraction methods can be hampered by co-extraction of lipophilic interfering substances, affecting chromatographic analysis.
• Developing efficient and clean extraction techniques is essential for reliable vitamin D metabolite profiling.

Purpose of the Study:

• To develop and validate a new solid-phase extraction (SPE) procedure for vitamin D and its major metabolites from plasma.
• To compare the efficiency and cleanliness of the new SPE method against a conventional extraction technique.
• To assess the separation capability of the new method for vitamin D and its metabolites based on polarity.

Main Methods:

• A two-step SPE procedure utilizing C18 cartridges followed by silica cartridges was developed.
• Plasma samples were extracted using both the new SPE method and a conventional extraction method.
• High-performance liquid chromatography (HPLC) was employed to analyze the extracted lipophilic material and assess sample cleanliness.

Main Results:

• C18 cartridges effectively extracted all tested vitamin D compounds.
• Subsequent chromatography on silica cartridges successfully resolved vitamin D and its metabolites according to polarity.
• The new SPE method yielded significantly cleaner sample fractions, particularly for vitamin D and 25-hydroxyvitamin D, compared to conventional methods.

Conclusions:

• The developed C18 and silica cartridge SPE procedure is superior to conventional methods for extracting vitamin D and its metabolites from plasma.
• This novel extraction system provides cleaner fractions, enhancing the reliability of subsequent chromatographic analysis.
• The method is suitable for comprehensive extraction and analysis of vitamin D and its key metabolites.