Methane will be measured on the gas chromatogram (Figure 9)using a FID (flame ioniza­tion) detector.

Note, unless you want smelly hands, it is recommended that you wear gloves. A lab coat is recom­mended for similar reasons.

• Using a 20 ml syringe connected to a 2-way stopcock, collect a little more than 5 ml of water from a port on your Winogradsky column.

• With the syringe pointing up, remove any air (tapping the sides of the syringe) and expel any extra water so that the final liquid volume in the syringe is 5 ml. Do this over a sink.

• Now, draw in 15 ml of air into the syringe so that the total air+water volume in the sy­ringe is 20 ml. Close the stopcock.

• Shake the syringe to equilibrate the methane between the air and water.

• With the syringe pointing down, eject all the water from the syringe into the sink and close the stopcock. Try to get all the water out, but leave at least 10 ml of gas in the sy­ringe

• We will now move to the GC lab in Starr 332 to measure methane.

• Repeat the above procedure for each of the ports on your Winogradsky column.