Ion/ion proton transfer reactions for protein mixture analysis

Area of Science:

• Analytical Chemistry
• Biochemistry
• Mass Spectrometry

Background:

• Electrospray mass spectrometry (ESI-MS) is crucial for analyzing biomolecules.
• Resolving ions with similar mass-to-charge ratios (m/z) presents a significant analytical challenge.
• Ion/ion reactions offer a potential solution for enhanced ion differentiation.

Purpose of the Study:

• To demonstrate the efficacy of ion/ion proton transfer reactions for improving ion resolution in ESI-MS.
• To showcase the detection of low-abundance contaminants in protein mixtures.
• To evaluate the use of quadrupole ion traps for high m/z ion analysis.

Main Methods:

• Utilized ion/ion proton transfer reactions as a method for ion manipulation.
• Applied electrospray mass spectrometry for sample analysis.
• Employed quadrupole ion trap technology for ion storage, reaction, and mass analysis.

Main Results:

• Successfully resolved ions with similar m/z ratios that were indistinguishable by conventional ESI-MS.
• Identified a minor contaminant protein in ribonuclease B solution.
• Detected previously unnoticed polymeric contaminants in a bovine serum albumin and bovine transferrin mixture.

Conclusions:

• Ion/ion proton transfer reactions are effective for resolving complex mixtures of proteins and biopolymers.
• Optimized ion trap parameters enhance the analysis of high m/z ions.
• This technique offers improved analytical figures of merit for high-mass biopolymer mixture determination.