Silicon surface assisted laser desorption ionization mass spectrometry for quantitative analysis.

Area of Science:

• Analytical Chemistry
• Mass Spectrometry
• Surface Science

Background:

• Quantitative analysis of organic compounds requires sensitive and reproducible methods.
• Existing laser desorption ionization techniques can suffer from reproducibility issues.
• Silicon substrates offer potential for developing novel ionization surfaces.

Purpose of the Study:

• To propose and evaluate a new approach for quantitative analysis using silicon Surface Assisted Laser Desorption Ionization Mass Spectrometry (Si-SALDI).
• To enhance the reproducibility and ionization efficiency of organic compounds using a laser-activated silicon surface.
• To demonstrate the application of Si-SALDI for quantifying pharmaceutical drugs in biological samples.

Main Methods:

• Formation of an active surface layer on a silicon substrate via direct laser radiation exposure within the mass spectrometer ion source.
• Repeated use of the same silicon substrate to ensure consistent ionization properties.
• Implementation of signal reproducibility improvement methods: continuous surface property monitoring, laser beam scanning, optimal laser fluence selection, and reproducible sample introduction.
• Application of the Si-SALDI approach for quantifying pharmaceutical drugs in blood extracts.

Main Results:

• The developed Si-SALDI method provides high reproducibility of surface ionization properties.
• High ionization efficiency for a range of organic compounds was achieved.
• The approach was successfully applied to quantify clinically relevant concentrations of pharmaceutical drugs in blood extracts.
• Methods for improving signal reproducibility were investigated and validated.

Conclusions:

• The proposed Si-SALDI approach offers a robust and reproducible method for quantitative analysis.
• This technique demonstrates significant potential for the sensitive quantification of analytes in complex biological matrices.
• Si-SALDI represents a valuable advancement in mass spectrometry-based analytical techniques.