Improving quantitative gas chromatography-electron ionization mass spectrometry results using a modified ion source:...

Area of Science:

• Analytical Chemistry
• Materials Science

Background:

• Electron ionization (EI) sources in mass spectrometry can exhibit signal drift, impacting quantitative accuracy.
• Residual solvents in medical device coatings require precise analytical methods for safety assurance.

Purpose of the Study:

• To investigate and mitigate signal drift in EI-mass spectrometry for residual solvent analysis.
• To optimize a static headspace-gas chromatography-EI-quadrupole mass spectrometry method for residual dichloromethane in coronary stent coatings.

Main Methods:

• A static headspace-gas chromatography-EI-quadrupole mass spectrometry method was developed and validated.
• Quantitative performance was compared between an original stainless steel ion source and a modified gold-coated ion source.
• Validation parameters included limit of detection, limit of quantification, linearity, and precision.

Main Results:

• The original stainless steel ion source showed significant signal drift, leading to poor linearity and precision.
• An internal standard did not fully compensate for signal drift due to differing drift patterns.
• The gold-coated ion source demonstrated improved signal stability, linearity, and precision, with enhanced sensitivity.
• Residual dichloromethane in coronary stent coatings was below the limit of quantification.

Conclusions:

• Gold coating of EI ion source components effectively reduces signal drift and improves quantitative performance.
• The modified ion source enables more reliable analysis of residual solvents in sensitive applications like medical device coatings.
• The optimized method confirmed low levels of residual dichloromethane in coronary stents.