抄録
<jats:title>SUMMARY</jats:title><jats:p>Some problems of the quantitative analysis of diffusible elements in cryosections are reviewed. The two prevalent methods for obtaining concentrations from X‐ray data, one based on characteristic radiation alone and the other on continuum‐normalization, are recapitulated. Both methods seem suitable at cellular level while the latter seems preferable at finer spatial resolution. Recourse to both methods together is desirable in the analysis of frozen‐hydrated sections especially when there is no peripheral standard.</jats:p><jats:p>Selective local contamination is a particular hazard in the analysis of chlorine. In the case of sodium, physical parameters set restrictive limits to the minimum concentration measurable by ‘energy‐dispersive’ X‐ray spectrometry (about 20 m<jats:sc>m</jats:sc> kg<jats:sup>−1</jats:sup>) and to the spatial resolution attainable by diffractive X‐ray spectrometry (∼0·2 μm).</jats:p><jats:p>One obvious danger to meaningful quantitative analysis is inadvertent redistribution of diffusible elements during the moments preceding the freeze‐quenching of a tiny piece of tissue. Data are presented to show that concentration changes due to simple evaporation are a real hazard prior to the quenching of sub‐millimetre size samples.</jats:p>
収録刊行物
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- Journal of Microscopy
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Journal of Microscopy 126 (3), 333-345, 1982-06
Wiley