Variable temperature trap

摘要

Volatile organotin compounds are concentrated and subsequently eluted to a detector which provides an indication of the concentration of the various compounds of interest. An elongate tube having a longitudinal chamber containing granular absorbent receives the gas sample. Liquid nitrogen covers the tube and brings the temperature down to about -198 DEG C. at which temperature the organotins of interest are trapped in the chamber. A helical coil about the tube then heats it to discrete temperatures at which temperatures discrete ones of the organotins of interest are eluted to an interconnected detector. Precise control of the temperatures allows precise analysis of the organotin and a later raising of the temperature to an even higher level rids the longitudinal chamber of other compounds and water vapor so that liquid nitrogen can be reintroduced to start another cycle.