Sensitivity automatic detection method and device of electron capture detector

Abstract

The invention relates to the technical field of detection and discloses a sensitivity automatic detection method and device of an electron capture detector. The automatic detection method comprises detecting current basic frequency of a voltage pulse in an electron capture detector, determining whether the detected current basic frequency exceeds a predetermined basic frequency range of the voltage pulse, outputting a judgment result, producing an adjustment command for adjusting a target current of the electron capture detector if the result shows that the detected current basic frequency exceeds the predetermined basic frequency range, and adjusting the magnitude of the target current in accordance with the adjustment instruction so that the electronic capture detector can adjust the basic frequency of the voltage pulse according to the adjusted target current. The method and device can automatically adjust the magnitude of the target current of the electron capture detector so that the signal-to-noise ratio of the measured chromatogram is not affected when the electron capture detector cavity is polluted or influenced by other factors so that high sensitivity of the electron capture detector is kept.

Description

technical field [0001] The invention relates to the technical field of detection, and more specifically, to an automatic detection method and device for the sensitivity of an electron capture detector. Background technique [0002] The existing more common fixed base current pulse modulation voltage-powered electron capture detector (ECD) such as figure 1 As shown, radioactive isotopes (such as 63 Ni radioisotope), when the carrier gas enters the detector cavity 1, it is ionized under the bombardment of β particles to form positive ions and free electrons; the free electrons are absorbed by compounds with electron affinity in the sample to form negative ions. The ion current can be measured by applying a pulse voltage to the detector electrodes. Since the migration speed of negative ions is much smaller than that of free electrons, it takes longer to reach the positive electrode and is easy to combine with positive ions, so the ion concentration decreases, the number of el...

AI Technical Summary

Problems solved by technology

However, at present, the adjustment of the target current is mainly done manually by the user. During the adjustment process, it is necessary to continuously observe the test results, that is, the chromatogram to determine a better target current. The adjustment process is cumbersome and seriously reduces the test efficiency.

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