Abstract: A manual sample injector includes a syringe holder, a plunger driver, and an interface. An interface-control lever attached to the interface can assume “extraction”, “injection”, and “safety” orientations. In its safety orientation, the interface-control lever maintains a syringe needle in a retracted position for safety. Mounting the sample injector on a sample vial forces the interface-control lever to its extraction orientation, which allows the syringe needle to extend into the sample vial for sample extraction. The extent of the needle into the sample vial can be adjusted for precise extraction of sample from non-uniform vial contents. Mounting the injector on an injection port forces the interface-control lever to its injection orientation so that the syringe needle can be extended to an appropriate depth for sample injection.

Abstract: A manual sample injector for a gas chromatograph comprises a syringe holder, a plunger driver including a volume-adjust assembly, an injection port interface, a release lever, and a force-calibration spring. The holder, driver, and interface collectively include guide rod and respective apertures so that the driver and interface can slide vertically relative to the holder. Pre-injection steps provide that the desired volume of sample is ready for injection. Injection steps include: mounting the injector on an injection port by sliding the port interface over a septum cap of the injection port, manually pushing the plunger driver, and thus the syringe holder, down against the resistance of the force-calibration spring until an actuator element of the port interface contacts the cocked release lever, increasing the downward force on the plunger driver so that the release lever is forced to a release position.

Abstract: A funnel-shaped monolithic low-density polyethylene sample-vial septum comprises a flange, a capture wall, a diffusion-barrier wall, and a membrane. The capture wall is conical, extending from its truncated apex at the diffusion barrier wall to its mouth about which the flange is disposed. The membrane is disposed at the end of the diffusion-barrier wall away from the capture wall. This structure defines a septum aperture, including a conical capture section, defined by the capture wall, and a cylindrical diffusion-barrier section, defined by the diffusion-barrier wall. The 7.0 mm length of the diffusion-barrier section is 12/mm times the square of its diameter 0.76 mm. The diameter of the diffusion-barrier section which is selected to be 0.05 mm greater than the diameter of the largest needle to be used with the septum, i.e., a 22 gauge needle typically used for liquid chromatography. The minimum thickness of the membrane is 0.

Abstract: A cap assembly for a gas chromatography injection port includes a two-piece septum. The two-piece septum includes a syringe seal for sealing an injection needle and a duckbill seal for sealing the injection port when the needle is not inserted. The syringe seal includes three annular ribs in its aperture. At the aperture base is a sealing rib that provides the main sealing function for the syringe seal. Just above the sealing rib is a stress-relief rib. At the top of the aperture is a wiping rib. The wiping rib wipes dust on the needle exterior so that it does not enter the aperture. Dust entering the aperture can be retained in the relatively large dust pocket between the wiping rib and the strain-relief rib. The septum is held in place by a septum nut that has a recess above the wiping rib for holding dust removed from the needle by the wiping rib. A washer in the recess prevents the syringe seal from deforming into the recess.

Abstract: A septum for an injection port of a gas chromatograph includes interlocked syringe and duckbill seals. The syringe seal prevents fluid leakage during injection by syringe. The duckbill seal prevents fluid leakage after the syringe needle is withdrawn from the septum. A spring clip is used to urge the duckbill closed as the needle is withdrawn. An advantage of this two component septum is that the duckbill slit can be precisely formed in the duckbill seal before the seals are engaged.