Quantitative analysis Analytical Chemistry Part 15 Summary PDF

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B. COLUMNMETHOD Quantitative analysis is also possible. The spot representing the component of interest can be cut (in the case of paper chromatography) or scraped from the surface (TLC), dissolved, and quantitated by some other technique, such as spectrophotometry. Column methods utilize a cylindr...

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Quantitative analysis is also possible. The spot representing the component of interest can be cut (in the case of paper chromatography) or scraped from the surface (TLC), dissolved, and quantitated by some other technique, such as spectrophotometry.

B. COLUMN METHOD Column methods utilize a cylindrical tube to contain the stationary phase, and the mobile phase moves through this tube either by gravity, with the use of a high pressure pump, or by gas pressure It is a solid-liquid technique in which the stationary phase is a solid & the mobile phase is a liquid or gas. Stationary phase is held in a narrow tube through which the mobile phase is forced under pressure or under the effect of gravity Types: 1. Open column chromatography 2. Instrumental chromatography  The mixture to be separated is placed at the

OPEN COLUMN CHROMATOGRAPHY 

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A type of chromatography that consists of a vertically positioned glass tube in which the stationary phase is placed It is typical for this tube to be open at the top (hence the name open-column chromatography), to have an inner diameter on the order of a centimeter or more, and to have a stopcock at the bottom All four types (adsorption, partition, ion exchange, and size exclusion) can be used with this technique. Stopcock – just like faucet to regulate the flow (stop and not to stop) raditional column chromatography is characterized by addition of mobile phase under atmospheric pressure and the stationary phase is packed in a glass column. top of the column and allowed to pass onto

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the stationary phase by opening the stopcock. The mobile phase is then added and continuously fed into the top of the column and flushed through by gravity flow. The mixture components separate on the stationary phase as they travel downward and are then collected as they elute from the column.

AUTOMATED – with machines and instruments – more efficient and faster than non-instrumental chromatography

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The components present into the mixture will travel downward and will be separated with the stationary phase A typical fraction collector consists of a rotating carousel of test tubes positioned under the column such that fractions of eluate are collected over a period of time A substance obtained from elution – ELUATE Elute - remove (an adsorbed substance) by washing with a solvent, especially in chromatography.

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INSTRUMENTAL CHROMATOGRAPHY 

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A column along with a continuous mobile phase flow system (that does not use gravity for the flow), a device for introducing the mixture to the flowing mobile phase, and an electronic sensor at the end of the column incorporated into a single unit These are Gas chromatography and highperformance liquid chromatography. Add a degree of efficiency and speed to the chromatography concept.

A separation technique that utilizes an electric field It is a general term that describes the migration and separation of charged particles (ions) under the influence of an electric field....