В горната статия, хората са ползвали фосфатен буфер, но целта не е била изолирането на фероцианата. Все пак:
"
Two stock solutions, 0.50 mM K3Fe(CN)6 solution in
0.10 M pH 7 phosphate buffer and a 0.060 M ascorbic acid,
are prepared by the instructor prior to the experiment. Approximately
30 mL of the ferricyanide solution and 1 mL of
ascorbic solution are required by each group of students...

The students are now ready to begin their titration. A
small aliquot, 5 µL, of 0.060 M ascorbic acid is added to the
beaker with the electrodes. We generally use micropipets for
the titration; it is critical to use small volumes of the titrant
since we are making the approximation that the total volume
of the solution is unchanged over the course of the experiment.
We found that a 5 µL aliquot of titrant is optimal
for the concentrations of solutions used; the students generally
measure 15–20 samples over the course of the titration.
Smaller volumes increase the length of the experiment while
larger volumes decrease the number of data points used in
the analysis.
After the ascorbic acid is added, the solution is allowed
to equilibrate for two minutes. After two minutes, the potential
and the absorbance at 420 nm are obtained; both readings
should decrease over the course of the titration. Another
aliquot of titrant is added at this point, and the entire process
is repeated until the solution appears to be colorless."

Тук се работи доста специфично, заради целта на ексеримента, разбира се - може да се адаптира.


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бял подпис на бяло поле