Abstract: The baseline drift occurring during a temperature or flow rate program in a chromatographic separating column is compensated for by signals from a function generator. The function generator supplies a computed baseline signal which is a representation of the baseline drift as an analytic function of the temperature, computed with specific separating column parameters. The parameters are determined in a prior test run and inputted into the function generator.

Abstract: A pocket instrument for sampling breath air in situ, includes a microprocessor-controlled directional control valve with needles at an outlet to which needle the sample vessels are attached. The directional control valve is arranged to be connected through another outlet to the atmosphere and to a collecting chamber respectively, which collecting chamber is provided with a feeding device for accommodating and delivering the breath air.

Abstract: In gas chromatography, the column ends of two capillary columns are inserted into a straight capillary from both sides forming annular gaps. The capillary is located in a tee out of which the capillary columns are sealingly guided, and to which carrier gas is supplied by means of a flushing flow conduit. A "straight-forward operation" having capillary columns connected in series and a "flush-back operation" are possible. The dead volume between the capillary columns can be kept small.

Abstract: Closure for a sample vial utilized to introduce sample into a gas chromatograph in accordance with the head space method. The closure includes a flexible disc for closing the opening through the neck of the vial and overlying the margin of the neck about the vial opening. A cap having a central aperture defining an annular shoulder about the aperture overlies the disc. The cap has an annular depending skirt encompassing the disc for clamping about the neck of the vial to retain the disc and the cap on the vial. A portion of the closure is deformable for venting the vial to atmosphere in response to a pressure within the vial when the closure is applied thereto in excess of a predetermined pressure.

Abstract: The sample device includes a magazine having a rotatable turntable carrying a plurality of circumferentially spaced chambers for receiving sample vessels and movable axially between a sample changing positon and a sampling position. In the sample change position, each sample vessel is pushed against a laterally displaceable closure plate to uncover an aperture in a bottom closure member whereby the sample vessel is receivable in a chamber registered with the aperture. A cradle is carried by the bottom closure member to support the sample vessel as it is displaced through the aperture into the registering chamber. When a selected vessel is aligned with a sampling opening through a closure plate on the opposite side of the turntable, the magazine is displaced axially into the sampling position with the axial displacement causing a needle to pierce the self-sealing diaphragm on the sample vessel.