• Separates substances w/in a mixture based on their physical properties• Used to: - analyze dyes in fibers - test for explosives or accelerants - check body fluids for drugs

• Paper Chromatography – small amount of substance placed near

bottom of paper, bottom placed in solvent- solvent moves up paper = mobile phase- paper itself = stationary phase

- As solvent moves, different components of mixture adhere to paper at different places

• Chromatogram – shows substances dissolved in original mixture & how far solvent traveled

• Rf value = retention factor - qualitative comparison b/t length of

time substance is in mobile & stationary phases

Rf = distance substance traveled distance solvent traveled - depends on type of solvent - solvent front = line where solvent stopped

moving

• Thin Layer Chromatography (TLC) - similar to paper, but faster &

clearer - use thin layer of gel-like material

on a glass or plastic plate - good to separate dyes & inks

• Gas Chromatography (GC) - at high temps - useful to separate mixtures w/

large molecules (ex. Proteins in blood)

• High Performance Liquid Chromatography (HPLC)

- at room temp - uses high pressure to force

mixtures through a column of liquid