Complete two-dimensional separation for analysis of acidic compounds in plasma using column-switching reversed-phase...

Area of Science:

• Analytical Chemistry
• Chromatography

Background:

• Accurate determination of acidic compounds in biological matrices like plasma is crucial for pharmacokinetic and toxicological studies.
• Existing methods may face challenges with complex sample matrices and achieving high sensitivity for specific analytes.

Purpose of the Study:

• To develop a complete two-dimensional separation technique for the determination of acidic compounds in plasma.
• To establish a method for the sensitive quantification of zidovudine-beta-D-glucuronide (AZT-beta-D-Gluc) and probenecid in rat plasma.

Main Methods:

• Utilized column-switching reversed-phase liquid chromatography with heart-cutting.
• Employed ion-pair chromatography with tetrabutylammonium ion in the second dimension for enhanced separation.
• Investigated retention behaviors and solute peak enrichment at the interface of the two columns.

Main Results:

• Achieved coincident solute peak enrichment and differential separation modes between the two columns.
• System suitability confirmed by high theoretical plate numbers in the second column post-heart-cutting.
• Successfully applied the technique to determine AZT-beta-D-Gluc and probenecid in rat plasma extracts at ng/ml levels with excellent separation from endogenous substances.

Conclusions:

• The developed two-dimensional liquid chromatography system provides complete separation for acidic compounds in plasma.
• The method enables sensitive and selective determination of target analytes, offering a valuable tool for bioanalysis.