A kind of automatic sample injector and sampling needle

Abstract

The invention discloses an automatic sample injector and a sampling needle. The automatic sample injector at least includes a sampling needle assembly. The sampling needle assembly includes: a sampling needle. The port is a sampling hole; a cylindrical connector is connected to the upper end of the sampling needle, the connector is positioned in the upper threaded mounting hole, the center of the connector is provided with a mounting groove, and the sampling tube is inserted into the mounting hole of the connector. In the groove, the lower port of the sampling pipe is engaged with the bottom surface of the installation groove and communicated with the upper port of the sampling needle; the upper joint and the upper blade ring are sleeved on the lower part of the sampling pipe, and the outer wall of the upper joint is connected with the sampling needle holder. The upper part of the threaded mounting hole is threaded; when the upper joint drives the upper edge ring to be pressed tightly on the connecting head, the lower port of the sampling tube is pressed against the bottom surface of the mounting groove and communicates with the upper port of the sampling needle. The invention has the advantages of simple manufacture, low cost, high sampling accuracy and less cross-contamination.

Description

technical field [0001] The invention relates to an automatic sample injector, in particular to a sampling needle with simple manufacture, low cost, high sampling accuracy and less cross-contamination and an automatic sample injector with the sampling needle. Background technique [0002] The sampling needle is a very critical part of the autosampler, which determines the injection accuracy and cross-contamination index of the autosampler. At present, due to the different structure of the motion mechanism of the sampling system of the sampler, the motion form of the sampling needle is also different. Generally, the sampling needle has two degrees of freedom and one degree of freedom. According to the different motion forms of the needle, the structure of the sampling needle has the following types: [0003] 1. The sampling needle of the back-end sleeve. Although the later installation and maintenance of this sampling needle is more convenient, the process of the sleeve is mo...

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Problems solved by technology

[0003] 1. The sampling needle of the back-end casing. Although the later installation and maintenance of this sampling needle is more convenient, the process of the casing is more difficult, and it is easy to generate a lot of air bubbles, which affects normal sampling.

[0004] 2. The sampling needle pipeline is directly manufactured with the sampling needle as an integral structure, which can be used for the injector of the push-in sampling method or the sampler of the sampling mechanism with the sampling needle only moving in the Z direction, and the scope of application is limited

[0005] 3. The back end of the sampling needle is connected to the pipeline through a two-way joint. Although the structure of this sampling needle is simple, the cost is relatively high;

[0006] 4. In addition, the sealing effect of the pipe fittings selected by the existing sampling needle is not ideal. The gap between the end of the pipe and the connection part of the sampling needle body is large, that is, the dead volume is large, it is not easy to clean, easy to store residues, and easy to produce Cross-contamination, affecting the accuracy of sampling

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