1. Methods of Separation
Unit 5

2. Hand Methods Hand sifting – Metal sifting –
used with large particles that can be separated with your fingers
Example – separating coins, colors of M&M
Metal sifting –
A magnet is used to separate metallics mixed in with nonmetallic items
Example – needles dropped in sand, iron chips dropped in sand

3. Evaporation Used to separate a solid dissolved in a liquid
The main goal is to obtain the solid
Example – boiling salt water to get the salt, boiling hot tea to get the tea

4. Filtering Used to separate chunks from a liquid
The chunks settle out easily and the liquid is thin
Example – filtering a watered down mud sample to obtain the unknown chunks in it (CSI)

5. Centrifuge
Used with mixture that have chunks that do not easily settle out
Example – a blood sample can be centrifuged to remove impurities, blue cheese dressing to get the chunks to come out

6. Liquid Chromatography
A liquid is used to separate different dyes from colors. The liquid will carry the colors up a paper by weight
Example – you did this with the marker lab. This is used when a signature could have been tampered with to see if the ink is the same.

7. Gas Chromatography
Used when a gas is moved in a gas chromatograph (an instrument) by its weight
Example – an unknown gas is brought back from Mars, the gas will be put into the gas chromatograph an the gases can be identified by how fast they move based on their masses

8. Distillation
Used to separate different liquids by the use of their boiling points. The mixture is heated and the liquid with the lower boiling point will evaporate quicker
Example – This is done to purify alcohol. The solution is boiled and the pure alcohol will evaporate off and is caught in anther flask (we will do this next unit)

9. Mass Spectroscopy
Used to identify different types of compounds in an unknown substance by their masses
This is used in CSI all the time. An unknown substance is found in put into a mass spec (instrument) the mass spec will analyze the substance based on its mass and identify it.