Improved accuracy and precision in electrophoretic NMR experiments. Current control and sample cell design

Area of Science:

• Analytical Chemistry
• Physical Chemistry
• Spectroscopy

Background:

• Electrophoretic NMR (ENMR) offers unique insights into physico-chemical properties.
• Experimental artifacts like thermal convection and electrolytic byproducts limit ENMR accuracy.
• Existing ENMR methods often require calibration with known standards.

Purpose of the Study:

• To present simple hardware and protocol modifications for ENMR.
• To significantly improve the accuracy and precision of ENMR measurements.
• To reduce common experimental artifacts in ENMR.

Main Methods:

• Utilizing a symmetric sample cell with controlled current feeding.
• Implementing a porous plug within the sample cell.
• Employing current-controlled pulses instead of voltage-controlled pulses for electric field application.

Main Results:

• Demonstrated significant reduction in thermal convection and electrolytic artifacts.
• Achieved enhanced experimental accuracy and precision in ENMR measurements.
• Validated the effectiveness of current-controlled pulses in artifact mitigation.

Conclusions:

• Modified ENMR protocols with current-controlled pulses and porous plugs substantially improve data quality.
• These modifications offer a more robust and reliable method for physico-chemical analysis using ENMR.
• The approach eliminates the need for calibration with samples of known electrophoretic mobility.