Configurations Analytical Chemistry Part 14 Summary PDF

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Summary

 Configurations can be broadly classified into two categories: Planar methods and the column methods It is a technique for separating dissolved species on the basis of their size. The stationary phase consists of porous polymer resin particles. The components to be separated can enter the pores o...

Description

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The two resins: anion and cation resins will exchange cations and anions to produce water

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The Salt is used for the ion

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Thus, the separation depends on the sizes of the pores relative to the sizes of the molecules to be separated.

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Porous – with pores (holes) Configurations canofbethis broadly classified into  The advantages method include good two categories: Planar methods and the separation of large molecules from the small column methods molecules Arrangement of chromatography

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It is a technique for separating dissolved species on the basis of their size.

Basis: SIZE Aka: Gel filtration chromatography 

The stationary phase consists of porous polymer resin particles. The components to be separated can enter the pores of these particles and be slowed from progressing through this stationary phase as a result.

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The mobile phase for this type can only be a liquid.

—physical state (gas or liquid) and positioning, and how and in what direction the mobile phase travels in terms of gravity, capillary action, or other forces.

A. PLANAR  The planar methods utilize a thin sheet of METHOD stationary phase material and the mobile phase moves across this sheet, either upward (ascending chromatography), downward (descending chromatography), or horizontally (radial chromatography).

2 types of chromatography under the planar method: 

Paper chromatography

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Thin Layer chromatography

PAPER CHROMATOGRAPHY 

Paper chromatography makes use of a sheet of paper having the consistency of filter paper (cellulose) for the stationary phase.

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Since such paper is hydrophilic, the stationary phase is actually a thin film of water unintentionally adsorbed on the surface of the paper.

Thus, paper chromatography represents a form of partition chromatography only.  The mobile phase is always a liquid. Why partition? Because the filter paper is hydrophilic – meaning it is just like a water uninterntionally absorbed on the surface of the water

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Capillary action is the ability of a liquid to flow in narrow spaces without the assistance of, and in opposition to, external forces such as gravity

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The most common stationary phase used – silica gel – highly polar stationary phase for adsorption chromatography Another common – pure cellulose – same material with paper chromatography thus under the Partition chromatography .

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material spread across a plastic sheet or T f c t

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WATER IS HELD IN THE PORES OF A FILTER PAPER  

It travels up in the paper. How attracted it is to the paper or the solvent depending on its chemical properties.

THIN LAYER CHROMATOGRAPH Y 

The stationary phase is a thin layer of

glass or metal plate. TLC can be any of the four types, including Rf factors  ratio of the distance traveled by ze component to the distance traveled by the solvent or id. the mobile phase ...