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 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: 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.

Abstract: A two-position rotary valve for injecting a liquid sample into a stream of solvent flowing through a liquid chromatographic column, without interrupting solvent flow is disclosed. The valve is switchable between a load position and an inject position. Associated with the valve is a sample loop whose downstream end is connected to a needle cavity axially extending along the valve rotor. In the load position the upstream end of the sample loop is vented to the atmosphere. This facilitates the loading of the sample into the sample loop through the needle cavity at atmospheric pressure with a conventional syringe needle. After sample loading the syringe needle is replaced by a wire-like plug which together with a compressible seal are capable of withstanding high pressure in the needle cavity when the latter is switched to the inject position. In this position solvent flows through the sample loop and the needle cavity from the solvent source to the column, forcing the previously loaded sample onto the column.