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--> coś się ostatnio na forum pojawiało.
Chromatografia ;) - powiazanie z ekstrakcją gazem etc.

fajny art:
http://www.chromatographyonline.com/lcgc/data/articlestandard//lcgceurope/382003/69718/article.pdf

Proste stare - ...

Early Investigations
The subject of Tswett’s Swiss PhD thesis had no direct
relationship to his future work, except that it was the first
demonstration of his interest in plant pigments. He selected
their study — mainly of chlorophyll — as the subject of his new
graduate thesis. Naturally, the first step in these investigations
was the extraction of the pigments from the leaves. He
observed that different solvents behaved differently. For
example, the pigments could be extracted easily from the leaves
with ethanol or acetone; however, petroleum ether (a mixture
of C5–C6 hydrocarbons) and ligroin (a mixture of higher
paraffins with a boiling point range of 135–145 °C), which
easily dissolve chlorophyll and other associated pigments when
they are available in isolated form, will extract only certain
pigments (using our present-day nomenclature, the
carotenoids) from the leaves, while chlorophyll will remain
there.
This observation was not new; however, past researchers
attributed it to solubility problems or a chemical change of the
structure of the pigments rendering them soluble or insoluble.
Not accepting this traditional thinking, Tswett assumed
correctly that the reason for this behaviour might be the
interference of some molecular forces binding the pigments to
the leaf substrate and that these forces depend upon the
individual pigments; for some, such as chlorophyll, they are
stronger than for others. Only solvents with a dissolving power
stronger than that of the binding molecular forces can be used
for the extraction of a particular pigment. On the other hand,
after the pigment is extracted and these molecular forces no
longer exist, even the weaker solvents can dissolve all the
pigments easily. Tswett correctly identified adsorption as the
basis of these molecular forces.

After drawing this conclusion the next logical step was to try
to imitate the process by using a substrate that would behave
similarly to the tissue of plant leaves. He selected filter paper,
which also consists of cellulose. After extracting the pigments
from the leaves with ethanol, he evaporated the solvent and
redissolved the residue in ligroin; next, he impregnated the
filter paper with this solution. The paper tainted with the
pigments behaved exactly in the same way as the original green
leaves: ligroin extracted only the carotenes, but after the
addition of a small amount of ethanol, all pigments could be
easily retrieved.
The title of his master’s thesis submitted to the University of
Kazan’ was “The Physico-Chemical Structure of the
Chlorophyll Particle: Experimental and Critical Study”,2,3 and
it represented a detailed report of these studies. This degree
finally qualified him for an appointment at a university, and he
applied immediately for a position at the University of Kazan’.
Meanwhile, however, an acquaintance of his from St.
Petersburg, D.I. Ivanovskii (the discoverer of the tobacco
mosaic virus) had just been appointed a professor of botany at
Warsaw University, and he invited Tswett to join him there.
Tswett accepted his invitation and moved to Warsaw at the end
of 1901.

Swoją szosą ciekawe - czym w takim wypadku spowodowane było całkiem sore przejście - zieleni do ekstraktu - na et.naftowym - przy ekstrakcji ciagłej. Może.. zanieczyszczeniem - .. et naftowego - acetonem/alkoholem../ przy przelewaniu - z butelki do butelki.. odzysku rozp? ;) - Tak mi sie skoj.. bo według tego co piszą .. prawie nie powinno iść.
No nie w tym.. a w innym: zara sie dorzuci.

No i nie zerowa obecność wody... W rozpuszczalnikach - odzyskiwanych ... hmm..
 
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