Coulometry-assisted quantitation in spray ionization mass spectrometry.

Area of Science:

• Analytical Chemistry
• Electrochemistry
• Mass Spectrometry

Background:

• Accurate quantification of analytes in complex mixtures is crucial for various scientific disciplines.
• Traditional methods often require extensive calibration and standard preparation, limiting their efficiency.

Purpose of the Study:

• To develop a novel, standard-free quantification method for analytes.
• To combine coulometric measurements with spray ionization mass spectrometry (MS) for enhanced analyte detection.

Main Methods:

• A three-electrode system on a polymer support was used for both electrochemical oxidation and spray ionization.
• Analyte concentration was determined by optimizing electrochemical oxidation, performing coulometric measurements, and analyzing ion intensities via MS.

Main Results:

• The developed method achieved accurate quantification with approximately 15% accuracy for model compounds like tyrosine, dopamine, and angiotensin II.
• The workflow demonstrated feasibility across diverse species, including endogenous metabolites and peptides.
• A practical application was shown through a bilirubin assay in urine.

Conclusions:

• This integrated coulometry and spray ionization MS approach offers a robust, standard-free platform for analyte quantification.
• The method's accuracy and versatility make it suitable for analyzing various biological and chemical samples.
• This technique holds potential for routine diagnostic assays and biochemical analysis.