On-line coupling of solid-phase microextraction to commercial CE-MS equipment

Area of Science:

• Analytical Chemistry
• Separation Science
• Mass Spectrometry

Background:

• Traditional methods for analyzing soil contaminants can be labor-intensive.
• On-line coupling of analytical techniques enhances efficiency and sensitivity.
• Solid-phase microextraction (SPME) and capillary electrophoresis (CE) are powerful separation techniques.

Purpose of the Study:

• To develop and validate a new on-line interface for coupling SPME with CE-MS.
• To analyze tetracycline antibiotic residues in soil samples.
• To assess the accuracy and reproducibility of the developed method.

Main Methods:

• A modified split-flow interface was designed to integrate a commercial SPME fiber with a CE system.
• The interface allows direct introduction of the SPME fiber into the CE capillary inlet.
• The system was optimized for analyzing tetracycline, oxytetracycline, and doxycycline in soil matrices.

Main Results:

• The developed interface demonstrated successful on-line coupling of SPME and CE-MS.
• Accuracy was confirmed by regression analysis of spiked soil samples at a 95% confidence level.
• Reproducibility was 5.3% relative standard deviation (RSD), with limits of detection (LOD) for tetracycline antibiotics ranging from 2.9 to 3.2 µg/kg.

Conclusions:

• The novel SPME-CE-MS interface provides a robust and sensitive method for soil contaminant analysis.
• The system is suitable for the routine determination of tetracycline antibiotic residues.
• The method offers good accuracy and reproducibility for environmental monitoring applications.