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18 Cards in this Set
- Front
- Back
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What is chromatography? |
-Physical method of separation -Components separated between stationary and mobile phase |
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What is the stationary phase in chromatography? |
-Remains stationary during testing -Contained in a layer or column -May be solid, gel, or liquid |
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-What is the mobile phase in chromatography? |
-Carries sample along the stationary phase -May be gas or liquid |
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How are solutes in a sample separated in chromatography? |
-They are separated as a result of their distribution between stationary and mobile phases -Mobile phase carries sample through something containing the stationary phase -As mobile phase flows past stationary - the solutes may: -Attach only on the stationary phase -Remain only in the mobile phase -Distribute between the two phases |
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Where do solutes with a higher affinity for the stationary phase reside? |
-They reside in the stationary phase and migrate slower |
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Where do solutes with less affinity for the stationary phase reside? |
-They reside mostly in the mobile phase and migrate faster |
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What types of chromatography are there? |
-Planar- the stationary phase is a flat surface -Paper -Solid surface -Column - the stationary phase is silica or polymer particles coated on inside of a column -Gas - mobile phase is gas -Liquid - mobile phase is liquid
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What is planar chromatography? |
-In paper chromatography or TLC, natural colors or chemical modification produces colored "spots" that can be measured -Qualitative or semi-quantitative -Visual exam to look for a spot -Compare location to a reference compound -Quantitative -Densitometer used to measure spot and compare to a reference compound |
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Can planar chromatography be qualitative, semi-quantitative, or quantitative? |
ALL: -Qualitative or semi-quantitative: -Visual exam to look for a spot -Compare location to a reference compound -Quantitative : -Densitometer used to measure spot and compare to a reference compound |
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What is column chromatography? |
-In GC or LC, mobile phase exits column and passes through a detector -Spectrophotometric, fluorometric, flame -Solutes displayed graphically as a series of peaks -Chromatogram |
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How is column chromatography analyzed? |
-Width -Height -Area -Qualitative or quantitative against reference compounds |
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What are the separation mechanisms? |
-Ion-exchange -Partition -Adsorption -Size-exclusion -Affinity |
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What is Ion-exchange Chromatography? |
-Separation based on an exchange of ions between a charged stationary surface and ions in the mobile phase -Anion exchange -positively charged groups in stationary phase -Cation exchange -Negatively charged group in stationary phase -Once completed an elution is done -Removal of what is now bound to column -Measure products in eluate |
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What is partition chromatography? |
-Separation depends on the solubilities of the sample components -Mobile phase - liquid -Stationary phase - liquid film attached to support surface -Immiscible with mobile phase |
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What is adsorption chromatography? |
-Separation depends on differences between the adsorption and desorption of solutes at the surface of the solid particle -Hydrogen bonding |
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What is size-exclusion chromatography? |
-Separation depends on the molecular size of the solutes -Stationary phase has different pore sizes -Smaller molecules go into pores and are "trapped" -Larger molecules pass through freely |
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What is affinity chromatography? |
-Separation depends on a specific biological interaction -Antigen-Antibody -Hormone-receptor -After mobile phase passes through, elution performed -Very specific |
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Describe HPLC |
In general, the smaller the diameter of the stationary phase particles or pores, the more efficient the column "high performance" -Highly sensitive and specific |
