Determination of pharmaceuticals in drinking water by CD-modified MEKC: separation optimization using experimental...

Area of Science:

• Environmental Chemistry
• Analytical Chemistry
• Separation Science

Background:

• Pharmaceuticals are prevalent contaminants in environmental waters.
• Effective analytical methods are needed for their detection and monitoring.
• Capillary electrophoresis offers a sensitive and efficient separation technique.

Purpose of the Study:

• To develop and optimize a capillary electrophoresis method for separating 12 common pharmaceuticals.
• To minimize analysis time while maintaining high resolution.
• To achieve sensitive detection limits for pharmaceutical contaminants.

Main Methods:

• Utilized highly sulphated cyclodextrin-modified micellar electrokinetic chromatography (CD-MEKC).
• Employed a face-centred composite experimental design for optimization.
• Optimized background electrolyte (BGE) composition, voltage, and capillary conditions.
• Coupled with Solid Phase Extraction (SPE) for enhanced sensitivity.

Main Results:

• Achieved baseline separation of 12 pharmaceuticals in 6.7 minutes.
• Optimized BGE: 10 mM ammonium hydrogen phosphate (pH 11.5), 69 mM SDS, 6 mg/mL sulphated beta-CD, 8.5% isopropanol.
• Separation voltage: 30 kV; Capillary: 48.5 cm x 50 µm id; Temperature: 30°C.
• Instrument LODs in the low mg/L range; SPE-enhanced LODs between 4–30 µg/L.

Conclusions:

• The developed CD-MEKC method is rapid and effective for pharmaceutical analysis in environmental water.
• The method provides sensitive detection limits, suitable for environmental monitoring.
• Experimental design efficiently optimized separation parameters for reduced run times.