Packaging and storage
Preserve in tight containers,protected from light.
Assay
Transfer 5.0mLof Spirit to a Babcock bottle,graduated to 8%,add 1.0mLof kerosene,and mix.Add saturated calcium chloride solution,acidified with hydrochloric acid,almost to fill the bulb of the bottle.Rotate the bottle vigorously to ensure mixing,and then add a sufficient quantity of the calcium chloride solution to bring the separated oil into the neck of the bottle.Centrifuge at about 1500rpm for 5minutes,and read the volume of oil in the stem.Subtract five divisions for the kerosene added,and multiply the remaining number of divisions by 4.2to obtain the volume,in mL,of peppermint oil in 100mLof the Spirit.