Determination of diclofenac using electromembrane extraction coupled with stripping FFT continuous cyclic voltammetry

Area of Science:

• Analytical Chemistry
• Electrochemistry
• Biomedical Analysis

Background:

• Accurate quantification of pharmaceuticals like diclofenac in biological matrices is essential for clinical diagnostics and therapeutic drug monitoring.
• Existing methods for diclofenac determination may lack the sensitivity or on-line capabilities required for rapid, trace-level analysis in whole blood.

Purpose of the Study:

• To develop and validate an on-line, ultra-sensitive method for determining trace amounts of diclofenac in whole blood samples.
• To optimize extraction parameters using a central composite design for enhanced efficiency.

Main Methods:

• Coupling of electromembrane extraction (EME) with stripping fast Fourier transform continuous cyclic voltammetry (SFFTCCV) using a carbon paste electrode.
• Optimization of EME parameters including applied DC potential (20 V), extraction time (28 min), sample pH (5), and acceptor solution pH (7).
• Analysis of diclofenac migration from a sample solution through a 1-octanol immobilized membrane into an acceptor solution.

Main Results:

• The developed method demonstrated good linearity for diclofenac detection in whole blood within the range of 5-1000 ng/mL (R² = 0.993).
• Achieved ultra-low limits of detection (LOD) of 1.0 ng/mL and quantification (LOQ) of 5.0 ng/mL.
• Successfully performed on-line and ultra-sensitive determination of trace diclofenac.

Conclusions:

• The integrated EME-SFFTCCV system provides a highly sensitive and efficient platform for the on-line determination of diclofenac in whole blood.
• This method holds significant potential for routine clinical analysis and pharmacokinetic studies requiring precise quantification of low diclofenac concentrations.