A compact visible-light spectrometric detector for capillary electrophoresis

Area of Science:

• Analytical Chemistry
• Spectroscopy
• Separation Science

Background:

• Portable analytical instruments are crucial for on-site sample analysis.
• Capillary electrophoresis (CE) offers high separation efficiency but often lacks portable detection capabilities.
• Miniaturized spectrometers enable compact spectral analysis.

Purpose of the Study:

• To develop a compact and portable capillary electrophoresis (CE) detector.
• To integrate a light-emitting diode (LED) excitation source and a mini spectrometer for visible light absorbance detection.
• To enhance compound identification by capturing full absorbance spectra.

Main Methods:

• Designed a robust portable CE detector with an adjustable slit for precise optical alignment.
• Utilized a light-emitting diode (LED) for excitation and a Hamamatsu C12880MA mini spectrometer for detection.
• Housed all components within a custom 3D-printed enclosure.
• Separated food colorants using the developed CE detector.

Main Results:

• Achieved dye detection limits near 40 μg/mL for food colorants.
• Demonstrated linear results from 20-1000 μg/mL with correlation coefficients over 0.999.
• Reported peak height relative standard deviations (RSDs) of 5-8%.

Conclusions:

• The developed portable CE detector provides a robust and compact solution for on-site analysis.
• Capturing full absorbance spectra enhances compound identification compared to standard portable CE detectors.
• The instrument shows excellent linearity and precision for food colorant analysis.