A New Quantification Method Using Electrochemical Mass Spectrometry

Area of Science:

• Analytical Chemistry
• Electrochemistry
• Mass Spectrometry

Background:

• Accurate quantification in mass spectrometry typically requires authentic or isotope-labeled standards.
• The unavailability or difficulty in synthesizing these standards presents a significant challenge for many analyses.

Purpose of the Study:

• To develop a novel quantification method combining electrochemistry (EC) and mass spectrometry (MS).
• To eliminate the need for external standards or calibration curves in analyte quantification.

Main Methods:

• Analyte undergoes electrochemical oxidation, followed by mass spectrometry analysis.
• Quantification is achieved by correlating electrochemical oxidation current (Faraday's Law) with MS signal changes.
• The method is integrated with liquid chromatography (LC) for mixture analysis.

Main Results:

• Successful quantification of various analytes including dopamine, norepinephrine, rutin, and glutathione with errors from -2.6% to +4.6%.
• Accurate measurement of analytes within complex matrices, such as uric acid in urine.
• Demonstrated applicability to mixture analysis using LC-EC-MS.

Conclusions:

• The EC-MS method provides a standard-free and calibration-free approach for accurate analyte quantification.
• This novel technique addresses a critical limitation in current mass spectrometry-based quantification.
• The method shows high accuracy and broad applicability in complex biological and chemical samples.