Many environmental processes cannot be accurately studied by the standard procedure of taking samples at a remote site of interest and analyzing them on laboratory instrumentation at a later time. This is particularly true for studies where measurements must be made rapidly in order to faithfully represent what nature is doing. In such circumstances, instrumentation that can be taken into the field for on-site measurements is required.
Many options are available for portable gas chromatographic instrumentation.
Some instruments are based on internal power supplies, and can therefore be used in nearly any environment, independent of whether or not line power is available. Other portable instruments require external power. While these instuments are less flexible in terms of locations in which they can be used, they also tend to have more features, since power requirements are not as big a limitation. Listed below are some companies that sell portable GC instrumentation. Note that this list consists only of those companies with whom I am familiar, and is by no means a comprehensive list.