Sample stacking by field-amplified sample injection and sweeping for simultaneous analysis of acidic and basic...

Area of Science:

• Analytical Chemistry
• Separation Science
• Biomedical Analysis

Background:

• Accurate quantification of acidic and basic drugs in complex matrices like plasma is challenging.
• Existing methods may require separate analyses for acidic and basic compounds, increasing complexity and time.
• Development of a single-run method for simultaneous analysis of both compound types is highly desirable.

Purpose of the Study:

• To develop and validate an online sample concentration technique for simultaneous detection and analysis of acidic and basic components.
• To apply this method for the quantification of drugs in commercial tablets and human plasma samples.
• To evaluate the method's precision, accuracy, and applicability in a clinical context.

Main Methods:

• Coupling of field-amplified sample injection (FASI) and sweeping techniques with micellar electrokinetic chromatography (MEKC).
• Utilizing successive anion- and cation-selective injections for simultaneous concentration of both acidic and basic analytes.
• Optimization of buffer composition (Tris, MeOH, PEO, SDS) and voltage parameters for effective separation and detection.

Main Results:

• The developed capillary electrophoretic method successfully detected and quantified acidic and basic drugs in a single run.
• High precision and accuracy were achieved, with intra- and interday variability below 6.1% for spiked plasma samples.
• The method was effectively applied to monitor drug concentrations in plasma samples from elderly patients.

Conclusions:

• The integrated FASI-sweeping-MEKC method offers a sensitive and efficient approach for simultaneous analysis of acidic and basic compounds.
• This technique provides a robust platform for drug quantification in pharmaceutical formulations and biological fluids.
• The validated method holds significant potential for therapeutic drug monitoring and pharmacokinetic studies.