Page "Inductively coupled plasma mass spectrometry" Paragraph 25

Argon can be purchased for use with the ICP-MS in either a refrigerated liquid or a gas form.

However it is important to note that whichever form of argon purchased, it should have a guaranteed purity of 99. 9 % Argon at a minimum.

It is important to determine which type of argon will be best suited for the specific situation.

Liquid argon is typically cheaper and can be stored in a greater quantity as opposed to the gas form, which is more expensive and takes up more tank space.

If the instrument is in an environment where it gets infrequent use, then buying argon in the gas state will be most appropriate as it will be more than enough to suit smaller run times and gas in the cylinder will remain stable for longer periods of time, whereas liquid argon will suffer loss to the environment due to venting of the tank when stored over extended time frames.

However if the ICP-MS is to be used routinely and is on and running for eight or more hours each day for several days a week, then going with liquid argon will be the most suitable.

If there are to be multiple ICP-MS instruments running for long periods of time, then it will most likely be beneficial for the laboratory to install a bulk or micro bulk argon tank which will be maintained by a gas supply company, thus eliminating the need to change out tanks frequently as well as minimizing loss of argon that is left over in each used tank as well as down time for tank changeover.