Gas chromatography column, with an ion mobility spectrometer cell, has an internal and controlled gas circuit where parameters and characteristics can be varied independently

摘要

The ion mobility spectrometer (IMS) is a cell (9) at a gas chromatography column (GC) with an internal and controlled gas circuit. A pump (6) and an analysis circuit filter (5) are linked to the sample gas outlet (9B) at the IMS cell, to take a sample gas flow (q2) through a branch channel (7). The outflow from the filter is passed to a splitter (4) which divides it into a small analysis gas part-flow (q2(1)) and a large analysis gas part-flow (q2(2)). The smaller part-flow passes through a reversible sample loop (2) and through the GC column (8) to the sample gas inlet (9A) at the IMS cell, and the larger part-flow is returned to the branch channel. A further gas flow (q1) is taken from another gas outlet (9C) at the IMS cell, in a path fitted with a pressure (12) and a temperature (13) sensor, through a second pump (11) and circuit filter (10), to an inlet (9D) at the IMS cell. The flow from the second filter can be divided into a drift gas part-flow and a further analysis gas part-flow.