0 Chromatography is a method of physically separating mixtures of gases, liquids, or dissolved...

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Transcript of 0 Chromatography is a method of physically separating mixtures of gases, liquids, or dissolved...

  • Chromatography is a method of physically separating mixtures of gases, liquids, or dissolved substances.Chromatography can be used to identify drugs, poisons and many other substances.Separation is determined by the molecular size and/or charge

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  • All forms of chromatography involve 2 phases The Two Phases1. stationary (absorbent) phase the material on which the separation takes place2. mobile phase - the solvent transports the sampleTypes of Chromatography - 5 of them

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  • Gas ChromatographyGas Chromatographya gas separates the componentsthey are then ionized and an electrical signal is recordedmobile phase - carrier gasstationary phase - thin film of liquid

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  • HPLCHigh Performance Liquid Chromatography (HPLC)- done at room temp. - advantageous for chemicals that are heat sensitive or volatile - example LSD- a liquid (mobile phase) is pumped through a column containing fine particles (stationary phase)

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  • TLCThin - Layer Chromatography (TLC)-A plate is coated with a granular gel - usually silica gel or aluminum oxide (stationary phase)- the substance to be separated is carried up the plate by capillary action - the substance with most affinity for the plate will rise the farthest.4. Paper chromatographySame as TLC but paperis used as stationary phase

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  • ElectrophoresisElectrophoresis - Similar to TLC but the substance is separated through a gel by electric current- Due to different size and charge substances will move across the plase at different speeds.

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  • Paper Chromatography of InkTwo samples of black ink from two different manufacturers have been characterized using paper chromatography.

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  • Retention Factor (Rf)A number that represents how far a compound travels in a particular solventIt is determined by measuring the distance the compound traveled and dividing it by the distance the solvent traveled.

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  • Solve for Rf

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