# Cryo-electron energy loss spectroscopy: observations on vitrified hydrated specimens and radiation damage.
> 凍結水和試料における電子エネルギー損失分光法と放射線損傷の観察


## Abstract

Valence-band EELS was applied to characterize frozen-hydrated specimens in electron microscopy. Energy-loss fine structure below 30 eV allowed discrimination between vitreous and crystalline ice phases, interpreted through molecular orbital transitions in water and solid-state excitons. Quantitative water content estimation in hydrated biological specimens was achieved by spectral decomposition into ice and organic contributions. Radiation chemistry under electron beam exposure was also investigated: detection of the hydrogen K-edge near 13 eV indicated that molecular hydrogen bubbles form at doses exceeding 10⁴ nm⁻², with internal gas pressures calculated to surpass one thousand atmospheres.

### Mechanism

Electron beam irradiation at doses above 10⁴ nm⁻² causes radiolytic decomposition of water molecules in frozen-hydrated specimens, generating molecular hydrogen bubbles detectable via the H K-edge at ~13 eV, with internal pressures exceeding 1000 atmospheres.

## Bibliographic

- **Authors**: Leapman RD, Sun S
- **Journal**: Ultramicroscopy
- **Year**: 1995
- **PMID**: [7571121](https://pubmed.ncbi.nlm.nih.gov/7571121/)
- **DOI**: [10.1016/0304-3991(95)00019-w](https://doi.org/10.1016/0304-3991(95)00019-w)
- **Study type**: other
- **Delivery route**: not specified
- **Effect reported**: not assessed

## Delivery context

The delivery route is not clearly identifiable from this paper. For hydrogen intake, inhalation is the most efficient route; inhalation, however, carries explosion risk (empirical LFL of 10%; high-concentration devices are not recommended).

## Safety notes

The delivery route is not clearly identifiable from this paper. For hydrogen intake, inhalation is the most efficient route; inhalation, however, carries explosion risk (empirical LFL of 10%; high-concentration devices are not recommended).

See also:
- [Inhalation concentration and LFL / UFL](https://h2-papers.org/en/safety-notes/inhalation-concentration)
- [Consumer Affairs Agency accident cases](https://h2-papers.org/en/safety-notes/accident-cases)

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> **Cite as**: H2 Papers — PMID 7571121. https://h2-papers.org/en/papers/7571121
> **Source**: PubMed PMID [7571121](https://pubmed.ncbi.nlm.nih.gov/7571121/)