Enhancing verapamil trace determination from biological matrices by bar adsorptive microextraction

Area of Science:

• Analytical Chemistry
• Pharmacology
• Biochemistry

Background:

• Verapamil is a vital L-type calcium channel blocker for cardiovascular conditions.
• Accurate therapeutic monitoring of verapamil is crucial in plasma, urine, and saliva.
• Existing analytical methods may require improvement for trace analysis in biological samples.

Purpose of the Study:

• To develop and validate a novel analytical method for verapamil determination.
• To utilize bar adsorptive microextraction and HPLC-DAD for enhanced sensitivity.
• To assess the method's applicability in real biological matrices.

Main Methods:

• Bar adsorptive microextraction with STRATA-CN and ENVI-18 reversed-phase polymers.
• High-performance liquid chromatography with diode array detection (HPLC-DAD).
• Optimization of sample pH, equilibrium time, stirring speed, and back-extraction solvent.

Main Results:

• High recoveries (56.01% to 96.82%) achieved under optimized conditions.
• Excellent linearity (r ≥ 0.99) from 20 to 600 ng mL⁻¹.
• Adequate precision (RSD% < 15%) and accuracy (RE% within 15%).

Conclusions:

• The developed method is sensitive and reliable for verapamil quantification.
• It is successfully applied to plasma, urine, and saliva samples.
• This novel approach presents a promising alternative for trace verapamil analysis in biological matrices.