Abstract: A frame is described, that is part of an injector which is used to load a sample at high pressure into a chromatographic column, wherein a tube coupling hole in the frame can not only couple to a standard 1/16th inch tube, but can also couple to a much smaller diameter tube which is useful for minimizing dispersion when small samples or small chromatographic columns are used. The tube coupling hole has a cylindrical inner end portion of a diameter substantially equal to the smaller tube diameter to closely receive it, a tapered middle portion, and a threaded outer portion. Ferrules for sealing tubes to the tapered hole portion, include a first ferrule having a hole that closely surrounds the smaller diameter tube, with the end of the tube lying in the cylindrical inner end portion. A second ferrule has a hole that closely surrounds the standard size larger tube, the tip of the larger tube lying against the tapered hole portion.

Abstract: An injector is described for injecting a sample at a high pressure into a chromatographic column, which avoids sample dilution that is characteristic of bypass loop injectors, and which also avoids significant flow interruption into the column that is characteristic of prior non-bypass injectors. The stator includes pump and column ports with openings (34a, 42a, FIG. 4) at the stator-rotor interface, where the openings are spaced by a small angle (m) of less than 10.degree. from one another. In the load position, a channel (50) formed in the interface surface of the rotor, which connects the pump and column openings in the load position, extends away from the pump opening by an angle (n) which is many times greater than the angle between the pump and column openings. As a result, as the injector is turned toward the inject position, the channel (50) continues to connect the pump and column openings until the rotor is close to the inject position. As the inject position is approached (FIG.

Abstract: An apparatus is described for withdrawing liquid samples from vials and injecting them into a chromatographic column or other analyzing device, which minimizes wastage, cross contamination, and dilution of the samples, and which can be automated with a minimum of complexity. The apparatus includes a sample loop for receiving a sample, and then delivering the sample by means of an injector valve into the flow stream of a chromatographic column, wherein an outer end of the loop is detachably connected to the valve by a loop end seal. The outer loop end can be lifted from the loop end seal and dipped into a vial, and a syringe connected via the valve to the inner loop end can be operated to draw sample liquid into the loop. The outer loop end then can be lifted from the vial and reinserted into the loop end seal, and upon operation of the valve the outer loop end is connected into the flow stream that is injected into the column to carry the sample to the column.

Abstract: A sample injector is described for receiving a sample at atmospheric pressure and injecting it at a high pressure into a chromatographic column, which is convenient to use and which avoids loss of the sample. The device includes a rotor and stator with flat adjacent faces, and a passage in the rotor for receiving a syringe needle that can transfer the sample into an aligned port in the stator, wherein the needle-receiving passage extends parallel to the axis of rotation of the rotor but is offset therefrom. This enables the needle to be inserted with its tip flush with the interface between the rotor and stator, so that no sample lies in the rotor passage after operation of the syringe, and so that rotation of the rotor isolates the syringe needle from the high pressure ports. With this arrangement, and with the needle end ground perpendicular to its axis, all of the sample in the syringe is transferred to the stator port and from there to the column.

Abstract: Several embodiments of a two-position rotary valve for injecting a liquid sample into a stream of solvent, flowing through a liquid chromatographic column, are disclosed. The valve is switchable between a Load position and an Inject position. The valve includes a needle cavity axially extending along the valve's rotor axis of rotation. The needle cavity is designed to accommodate a syringe needle from which a sample is loaded into one end of a sample loop which is externally connected to the valve, while the opposite end of the loop is vented to the atmosphere, when the valve is in the Load position. This facilitates the loading of the sample into the sample loop through the needle cavity at atmospheric pressure with a conventional syringe needle. In the Inject position solvent is made to flow through the sample loop in order to eject the sample from the loop and inject it onto the column.