Analyte-Size-Dependent Ionization and Quantification of Monosaccharides in Human Plasma Using Cation-Exchanged...

Area of Science:

• Analytical Chemistry
• Materials Science

Background:

• Matrix-assisted laser desorption/ionization mass spectrometry (MALDI MS) is a powerful analytical technique.
• Developing new matrices can enhance MALDI MS performance, particularly for specific analyte classes.

Purpose of the Study:

• To develop and evaluate a novel inorganic matrix based on smectite for MALDI MS.
• To assess the matrix's suitability for analyzing small molecules, specifically saccharides.

Main Methods:

• Smectite, a synthetic saponite polymer, was intercalated with organic matrix molecules (THAP, DHBA).
• The smectite-matrix complex was used in laser desorption/ionization mass spectrometry.
• Analyte ionization efficiency was investigated based on molecular size and preparation methods.
• Quantitative analysis was performed using an isotope-labeled internal standard.

Main Results:

• The smectite-based matrix allowed ionization of small analytes that could enter its layer spacing.
• Homogeneous distribution of matrix molecules within smectite layers resulted in high peak intensity reproducibility.
• Quantitative analysis of monosaccharides in human plasma yielded a concentration of 8.6 ± 0.3 μg/mg.

Conclusions:

• Smectite-intercalated organic molecules represent a viable new matrix for MALDI MS.
• This approach offers improved reproducibility for the analysis of small molecules.
• The method is suitable for quantitative analysis of monosaccharides in biological samples like plasma.