Abstract: A dosing device has a flow divider connected between a carrier gas source and a gas chromatography separating column, in particular a capillary column. The flow divider has a conduit with an opening and a chamber surrounding said conduit with a delivery line for the gas sample. The gas sample is taken from the sampling gas source through a metering valve with a metering loop at low pressure and passed, together with the carrier gas at higher pressure, into the flow divider. A pressure drop can be reversed by means of a reversing valve connected to the carrier gas source so that in a first switching position the sample can enter the chamber and in a second switching position a fraction of the sample corresponding to the dividing ratio in the flow divider can pass through the opening in the conduit into the separating column.

Abstract: Upstream and downstream flow dividers are connected in series between a sample dispenser and a gas chromatograph separation column. The downstream flow divider is connected to a source of carrier gas, and the system can be backflushed with carrier gas to remove residual quantities of sample material and elute the sample.