Automatic sample injector for liquid chromatograph

Abstract

The invention discloses an automatic sample injector for a liquid chromatograph. The automatic sample injector for the liquid chromatograph comprises a sample injecting passage and a six-way valve, wherein the front end and the tail end of the sample injecting passage are connected with a chromatographic column and a liquid conveying pump respectively; the sample injecting passage comprises a sample injecting needle, a first pipe, and a needle holder into which the sample injecting needle is inserted; the mutual communicated states of ports of the six-way valve are changed through channel switching; the six-way valve comprises a first port connected with the liquid conveying pump, a second port connected with the first pipe, a third port connected with the needle holder and a fourth port connected with the chromatographic column; during sample injecting, the first port is communicated with the second port and the third port is communicated with the fourth port; the liquid conveying pump is communicated with the first pipe through the first port and the second port; the needle holder is communicated with the chromatographic column through the third port and the fourth port. Comparedwith the traditional sample injector, the automatic sample injector for the liquid chromatograph, provided by the invention, has the advantages as follows: the sample injector provided by the invention can achieve precise sample injection without using a quantifying loop; the sample injector provided by the invention can conveniently change the sampling volume, so that the trouble of detaching and mounting the quantifying loop of the conventional sample injector is eliminated; the sample injector provided by the invention can also significantly reduce sample residue, is not required to be repeatedly cleaned, and has improved sample injecting efficiency.

Description

technical field [0001] The invention relates to the field of chromatographs, in particular to an automatic sampler for liquid chromatographs. Background technique [0002] In recent years, liquid chromatographs have developed rapidly in the direction of automation, and the emergence of autosamplers has greatly improved laboratory efficiency and reduced labor costs. The autosampler has been continuously improved around reducing sample residue, improving repeatability, improving work efficiency, convenience, and ease of use. [0003] In order to ensure repeatability, current autosamplers generally use a fixed-volume pipeline called a quantitative loop. When it is necessary to change the injection volume of the sample, it is necessary to replace the quantitative loop of another volume. The replacement process is cumbersome and easily damages the instrument. In order to reduce the influence of the previous sample on the latter sample, the autosampler of the liquid chromatogra...

AI Technical Summary

Problems solved by technology

[0008] The purpose of the present invention is to provide a liquid chromatograph automatic sample injector, aiming to solve the problem of troublesome disassembly and assembly of the quantitative loop of the current liquid chromatograph sample injector and time-consuming flushing of the sampling needle

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