Enhancing the MALDI-TOF MS Detection Mass Range of Saccharides Using a Reactive Composite Matrix

Area of Science:

• Analytical Chemistry
• Biochemistry
• Glycobiology

Background:

• Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) is crucial for saccharide analysis.
• Low ionization efficiency, especially for high-molecular-weight polysaccharides, limits MALDI-TOF MS sensitivity.
• Existing methods struggle with comprehensive saccharide profiling.

Purpose of the Study:

• To develop a novel composite matrix for enhanced saccharide detection in MALDI-TOF MS.
• To overcome the limitations of low ionization efficiency in saccharide analysis.
• To enable robust profiling of diverse saccharides, including polysaccharides and N-glycans.

Main Methods:

• Development of a composite matrix using 4-hydrazinoquinazoline (4-HQ) and caffeic acid (CA).
• Optimization of the 4-HQ/CA ratio, reaction temperature, and time using dextran 6k as a model.
• Application of the optimized matrix for direct profiling of saccharides in complex biological and food samples.

Main Results:

• The 4-HQ/CA matrix demonstrated synergistic enhancement of saccharide ionization efficiency.
• Successful direct profiling of oligo/polysaccharides in inulin and garlic extracts.
• Effective detection of N-glycans from ovalbumin and fetuin.
• Superior performance over conventional 2,5-dihydroxybenzoic acid (DHB) for non-reducing saccharides, yielding higher signal-to-noise ratios.

Conclusions:

• The novel 4-HQ/CA composite matrix significantly improves MALDI-TOF MS analysis of saccharides.
• This approach enhances detection of both reducing and non-reducing saccharides, expanding analytical capabilities.
• The matrix shows great potential for routine saccharide analysis in glycobiology and food science.