Thermal desorption double-channel sample tube transfer system

Abstract

The invention relates to a thermal desorption dual-channel sample tube transfer system, which solves the problems of removal, capping, loading and transfer of a multi-channel sample tube. One side of the sample disc is provided with at least one sample tube output interface opposite to a coaxial tube lifting seat interface below the sample tube output interface, the tube lifting seat interface is connected with a gas circuit of the tube lifting seat interface, a horizontal inlet and outlet space of a sample tube heater is arranged between the sample tube output interface and the tube lifting seat interface, and the sample tube heater is in horizontal transmission connection with a driver; a manipulator rotating center is arranged on one side of the sample tube heater, a tube clamp of the manipulator is vertically coaxial with a tube cap clamp of the uncapping and capping frame after the manipulator rotates by 90 degrees anticlockwise, and a tube taking position of the manipulator is arranged on an intersection point of a connecting line of two points of the manipulator rotating center and the center of the sample plate and a circumference where the sample tube on the sample plate is positioned; the manipulator rotates to enable the center of the pipe clamp mounted on the manipulator to rotate to a straight line of a connecting line of the rotating center of the pipe clamp and the center of the sample disc.

Description

technical field [0001] The present invention is concerned with the transfer of a substance to be tested through a thermal desorption sample tube containing an adsorbent. Background technique [0002] The thermal desorption mentioned here is also called thermal desorption, which is an important pre-treatment equipment for gas chromatography to detect air quality, volatile and semi-volatile organic compounds in the air. Due to the low content of volatile and semi-volatile organic compounds in the air, the sensitivity of general gas chromatographs cannot meet the requirements. However, although the content is very low, people are breathing at any time, and its cumulative amount is very large, so it is necessary to detect it. Therefore, it is necessary to use a method to absorb and concentrate the substance to be tested through a sample tube equipped with an adsorbent, and then inject the sample through thermal desorption and desorption. However, the volume of the sample tube is...

AI Technical Summary

Problems solved by technology

Due to the low content of volatile and semi-volatile organic compounds in the air, the sensitivity of general gas chromatographs cannot meet the requirements, but despite the low content, people are breathing at any time, and its cumulative amount is large, so it is necessary to detect

Therefore, it is necessary to use a method to absorb and concentrate the substance to be tested through a sample tube equipped with an adsorbent, and then inject the sample through thermal desorption and desorption. However, the volume of the sample tube is large, and the speed of directly desorbing the component to be tested is slow, resulting in The resolution of the chromatographic peaks is low, which cannot meet the requirements of the resolution of the capillary chromatographic column. It is necessary to desorb the sample tube components and then enter the cryogenic cold trap tube to focus and then desorb the sample to obtain the chromatographic peak resolution.

[0003] Since the quality of the packing inside the sample tube has a great influence on the sampling and test results, it is required to protect the internal packing and ensure the test results when desorbing the sample tube. It is necessary to purge the air and moisture inside the sample tube first, so the sample It is very important to connect the tube into the desorption channel and the gas path at both ends. There are generally two ways on the market: one is that the sample tube is inserted into the gas path interface at both ends, and the outlet end is heated to the entire sample flow path. The O-ring is sealed, and the carrier gas blows back the sample tube through the outlet end, which can well remove the air in the tube and prevent the inner packing of the sample tube from being oxidized at high temperature; the other is relatively simple to use rubber pads at both ends of the sample tube Sealing, insert the needle from both ends to ventilate and purge the air. The big problem is that the air between the needle and the inner wall of the tube is difficult to completely blow out, which will directly lead to the destruction of the sample tube packing at high temperature, shorten the life, and increase the cost.

Of course, there is also a connection method with a one-way valve at both ends of the sample tube. The disadvantages of this method are that the inside of the one-way valve is complicated, it is not easy to be heated, there is large interference, and the residue is high.

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