For the separation of beryllium,
magnesium, calcium, strontium and barium by
paper chromatography, a solvent- mixture, which
is claimed to be superior to any previously
devised for these elements, is described.
This solvent -mixture may be used for a qualitative and semi -quantitative analysis of a
mixture of these cations.A method is described, whereby micromole
amounts of magnesium and the alkaline earths,
separated by paper chromatography, may be
titrated spectrophótometrically with di- sodium
di- hydrogen ethylene diamine tetra -acetate
reagent. The method should be Particularly
useful for the analysis of Group IIA elements
in a material of which no more than 5 mg. is
available. The application of the classical
methods of analysis to such a sample would be very
difficult if they could be applied at all.A solvent -mixture is described for the
qualitative and semi -quantitative analysis
of a mixture of alkali metal and ammonium salts.
Although all six cations are not separated on
the one chromatogram, selective spraying reagents
make such an analysis possible. Methods are
also suggested for the quantitative determination
of potassium, rubidium and caesium, after
their separation by paper chromatography.A solvent- mixture for the qualitative
analysis of mixtures of the Group IIIB elements
and certain aluminium alloys, is proposed.It is worth noting that the whole analysis
for the detection and semi- quantitative
estimation of the ten metals in Groups IA and
IIA has been carried out on 0.03 ml. of solution
containing never more than 20 FM of cations
(i.e. < 3 mg.). 0.01 FE amounts of any of
these cations, with the exception of lithium for
which 0.25 FM is required, can be separated
and detected in a mixture of 10 FM of the
cations in the same group.The results of certain of these researches
have been published in the 'Analyst' in a paper entitled, "The Separation of Group IIA
Elements of the Periodic Table by Paper
Chromatography". A reprint of the paper is
enclosed. Another paper entitled, "Chromatographic Separations in phenol - Methanol - Hydrochloric Acid Solvents; with special
reference to Alkali Metals" will shortly appear
in the 'Analyst'
