For 10 points, name this lab technique that comes in gas, column, and thin-layer varieties and is named for the colors it can create.
One form of this technique analyzes the output using thermal conductivity or flame ionization detectors. All forms of this technique measure some sort of retention time or retention factor. Another form of this technique uses a tube packed with silica gel and works because more polar components will take longer to pass through the tube. A third form of this technique "spots" drops of liquid on a plate and uses capillary action to draw solvent upwards. This technique involves the use of a mobile phase moving over a stationary phase to separate a mixture. For 10 points, name this lab technique that comes in gas, column, and thin-layer varieties and is named for the colors it can create.
One form of this technique analyzes the output using thermal conductivity or flame ionization detectors.
chromatography [accept more specific answers as well, such as gas chromatography]