A. Patak et al., EVALUATION OF SEVERAL COMMON STANDARDS FOR THE X-RAY-MICROANALYSIS OFTHIN BIOLOGICAL SPECIMENS, Journal of Microscopy, 170, 1993, pp. 265-273
The question of the best type of standard to use for X-ray microanalys
is of thin biological specimens remains unanswered. Standards embedded
in an organic matrix have the advantage that they resemble biological
specimens, but their composition is generally not known exactly. We c
ompared several standards and, surprisingly, inorganic binary salts sp
rayed onto a supporting film were the most suitable: they corresponded
closely with several other methods using organic matrices; they were
easily produced: and their composition is known. Glutaraldehyde-urea a
minoplastic resin thin sections and thin films containing dissolved sa
lts were problematic. The composition of the polymer appears to be var
iable, and the thin films did not correspond with any other standard t
ested. Chelex100 bio-standard beads and flakes loaded with accurately
determined concentrations of ions, embedded in epoxy resin and thin se
ctioned, tended to correspond to the results obtained with the binary
salts. However, the results from some bio-standards were inexplicably
aberrant. An epoxy resin standard was used for bromine, and was found
to agree closely with the binary standards.