Compounds:

• Bromomethane (methyl bromide) (74-83-9)
• Chloroethane (ethyl chloride) (75-00-3)
• Chloromethane (methyl chloride) (74-87-3)
• Trichlorofluoromethane (CFC-11) (75-69-4)
• Vinyl chloride (75-01-4)

Achieving the Best Results from Gas Standards

In order to achieve the best results from gas standards, proper handling and storage of gas solutions is of vital importance. Use the following tips to help ensure trouble-free performance:

• Before opening the sealed ampul, gently invert the ampul several times. This will redissolve any gases that may have migrated into the headspace of the ampul.
• When diluting a gas standard, always add it to a solvent. Adding the gas standard to an empty vessel prior to adding solvent will result in the loss of gas compounds.
• Keep the gas standard cold throughout its use. Make sure it is cold before opening the ampul, work quickly to minimize heat transfer from hands or room, and only dilute the standard into a very cold solvent.
• When diluting a gas standard in solvent, make sure the pipette or needle tip is directly above, or immersed below, the solvent surface.
• Restek recommend that any unused portion of gas standard be disposed of after it has been removed from the sealed ampul. If it is necessary to store the unused portion, place it into a tightly capped vial with little to no headspace and store it in the freezer.
• Restek recommend that any gas solutions that have been stored outside of a sealed ampul be disposed of after 7 days.