Beam induced mass loss in high resolution biological microanalysis.

Area of Science:

• Materials Science
• Biological Sciences
• Analytical Chemistry

Background:

• Electron beam microscopy is crucial for analyzing biological samples.
• Electron beam irradiation can induce mass loss, affecting analytical accuracy.
• Understanding beam-induced damage is essential for reliable results.

Purpose of the Study:

• To quantify electron beam induced mass loss in biological samples.
• To investigate the impact of temperature on beam damage.
• To assess the loss of specific elements like sulfur.

Main Methods:

• Utilized Energy-Dispersive X-ray Spectroscopy (EDS) to monitor spectral changes.
• Measured bremsstrahlung and elemental peak variations under electron beam exposure.
• Corrected for experimental artifacts like contamination and drift.
• Compared results at room temperature (296 K) and low temperature (93 K).

Main Results:

• Significant mass loss observed in organic matrix and higher Z elements.
• Average bremsstrahlung losses were 45-50% for different sample types.
• Average sulfur losses ranged from 72-86%.
• Low-temperature (93 K) irradiation initiated damage at higher doses, with reduced sulfur loss.

Conclusions:

• Electron beam irradiation causes substantial mass loss in biological samples, especially sulfur.
• Temperature plays a critical role in mitigating beam-induced damage.
• Low-temperature microscopy is recommended for preserving sample integrity and improving analytical accuracy.