Term
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Definition
- combines two immiscible liquids, one of which easily dissolves the compound of interest
- polar layer is the aqueous phase and dissolves compounds with hydrogen bonding or polarity
- nonpolary layer is called the organic phase and dissolves nonpolar compounds
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Term
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Definition
| the reverse of extraction, in which a small amount of solute that dissolves impurities is run over the compound of interest |
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Term
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Definition
- isolates a solid (residue) from a liquid (filtrate)
- gravity filtration - used when the product of interest is in the filtrate
- vacuum filtration - used when the product of interest is a solid
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Term
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Definition
- the product is dissolved in a minimum amount of hot solvent; if hte impurities are more soluble, the crystals will reform while the flask cools, excluding the impurities
- takes advantages of differences in solubility
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Term
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Definition
- separates liquids by differences in boiling points; liquid with lowest boiling point will vaporize first and be collected as distillate
- simple distillation - used if the boiling points are under 150oC and are at least 25oC apart
- vacuum distillation - used if the boiling points are over 150oC to prevent degradation of the product
- fractional distillation - used if the boiling points are less than 25oC apart because it allows more refined separation of liquids by boiling point
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Term
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Definition
- use two phases to separate compounds based on physical or chemical properties
- stationary phase or adsorbent is usually polar
- mobile phase runs through stationary phase
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Term
| thin layer chromatography |
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Definition
| used to identify a sample; stationary phase is polar and commonly silica, alumina or paper |
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Term
| ion-exchange chromatography |
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Definition
| type of column chromatography that uses beads coated with charges substances to bind compounds with the opposite charge and separate compounds based on ionic properties |
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Term
| size-exclusion chromatography |
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Definition
| type of column chromatography which uses beads with small pores which trap smaller compounds and allow larger compounds to travel through faster; separates based on size |
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Term
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Definition
| a form of column chromatography that usees beads coated with a receptor or antibody so that they have a high affinity for a specific compound |
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Term
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Definition
separates vaporizable compounds according to how well they adhere to the adsorbent in the column
- the stationary phase is a coil of crushed metal or a polymer
- the mobile phase is a nonreactive gase
- may be combined in sequence with mass spectrometry
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Term
| high-performance liquid chromatography |
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Definition
| uses sophisticated computer-mediated solvent and temperature gradients; it is used if the sample size is small or if forces such as capillary action will affect results |
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