Headspace versus direct immersion solid phase microextraction in complex matrixes: investigation of analyte behavior...

Area of Science:

• Analytical Chemistry
• Separation Science
• Metabolomics

Background:

• Solid-phase microextraction (SPME) is widely used for analyte extraction.
• Understanding analyte behavior in complex matrices is crucial for accurate quantification.
• Matrix effects and coating saturation can compromise SPME performance.

Purpose of the Study:

• To investigate factors influencing analyte uptake in complex matrices using SPME.
• To compare different SPME coatings and extraction modes for improved performance.
• To evaluate the suitability of SPME for in vivo and ex vivo applications in metabolomics.

Main Methods:

• Utilized commercially available liquid and solid porous SPME coatings.
• Investigated aqueous systems with varying analyte properties (hydrophobicity, MW, functionality).
• Simulated ex vivo and in vivo sampling conditions using a starch matrix model.

Main Results:

• Headspace SPME showed more pronounced coating saturation compared to direct immersion.
• Direct immersion SPME enhanced extraction of polar compounds and minimized saturation artifacts.
• PDMS-modified coatings reduced saturation artifacts and demonstrated matrix compatibility.
• Matrix handling can disrupt analyte/matrix equilibria, leading to potential coating saturation.
• Direct immersion SPME proved suitable for in vivo applications.

Conclusions:

• Direct immersion SPME is a practical quantification approach, particularly for metabolomics.
• PDMS-modified coatings offer advantages in reducing artifacts and enhancing matrix compatibility.
• SPME, especially direct immersion, is suitable for in vivo quantitative metabolomics in complex systems like plants.