The concepts, principles and classifications of layering technology (gel and ion exchange)

I. Concept
A technique for separating matter through two phases by taking advantage of the differences in the physical and chemical properties of the various parts in the mix (absorption force, molecular shape, size, molecular polarity, molecular affinity, and distribution coefficients).
Early this century (1903), Russian botanist M.C. Jber discovered and used this technique to prove that the leaves of plants contained not only chlorophytes, but also other pigments, in fact, the adsorption layer he used. Now stratification has become one
effective separation and

in
, biochemistry, molecular biology and other disciplines., principle
specific processes:seine substances: sugars,
organic
acids,
amino acids
,
nucleotides
.
third, classification
. 1. Classification by physical state of the two phases
gas phase layering: gas-liquid layering (fixed phase is liquid) and gas solid layering (fixed phase is solid), and flow phase is gas.
liquid phase layering: liquid layering (fixed phase is liquid) and liquid solid layering (fixed phase is solid), flow phase is liquid.
2.Classified by the
column analysis: fixed phase mounted in the column, so that the sample moves in one direction and separates.
thin layer analysis: the appropriate viscosity of the fixed phase evenly spread on the sheet, dot the sample, with the flow phase to expand.
paper analysis:
filter paper
as a carrier of liquid, dot the sample and then expand with the flow phase.
3.According to the classification of the principle of layering: common classification method
(1) adsorption layering: fixed phase is a solid adsorption agent, through different solute adsorption force is different separation.
(2) distribution analysis: the distribution coefficients in the two phases are different.
distribution coefficient: When a solute is distributed among two given insoluble solvents, after equilibrium is reached at a certain temperature, the concentration ratio of the solute in the two phases is a constant, i.e. the distribution coefficient (Kd)
. Kd-Ca/ Cb
Ca and Cb represent the concentration of a substance in two insoluble phases, phase A (dynamic phase) and phase B (static phase), respectively.
(3) Ion exchange layering: fixed phase is an ion exchange agent, each group is different from its affinity
(4) gel layering: fixed phase is porous gel, according to the molecular weight difference of the solute in the flow phase to separate
(5) affinity layering: Using the mating base with special affinity effect on the surface coupling of the fixed phase carrier, it is separated
(6) metal chelating layer analysis
(7) hydrophobic layering
(8) inverting layer analysiswith the reversible specific binding of the solute molecule.