Sample analysing method and apparatus

摘要

An analytical method in which a first flow of inert gas is passed through a sample tube (ST) and a trap (TT) in succession whilst the sample tube (ST) is heated and the trap (TT) is cooled. The sample tube (ST) contains a sorbent material (10) on which one or more volatile substances have been adsorbed or absorbed and the trap (TT) contains a smaller quantity of material which serves to adsorb or absorb the volatile substance(s) liberated from the sample tube (ST). A second flow of gas is subsequently passed through the trap (TT) and a sensor device (D) in succession whilst heating the trap (TT). The method thus improves the analytical signal provided by the sensor device (D) by concentrating the volatile substance(s) in the second flow of gas. <IMAGE>