Gas chromatography is a physical separation method. Using material components to be tested in two different alternate with subtle differences in the distribution coefficient (solubility), when two phase for relative motion, these substances in the distribution of the two phases to repeatedly, make originally only the nature of the minute differences produce very big effect, and make the different component separation and leave the chromatographic column into the detector according to the order on the recorder describe the chromatographic peak of each composition.

The hydrogen flame is used as the ionization source. When the gas to be measured passes through the ion chamber, the molecules are ionized directly or indirectly under the action of energy, and the current is formed by directional movement in the electric field. The intensity of the electron current is measured by using the electronic amplification system, and the change signal of the substance to be measured can be obtained.

Thermal conductivity detectors are based on different substances having different thermal conductivity coefficients. When the sample is not injected, the temperature and resistance of the tungsten wire in the two holes decrease equally. During sample injection, the carrier gas passes through the reference tank, and the carrier gas flows through the measuring tank with the sample component, because the thermal conductivity of the mixture composed of the component and the carrier gas is different from that of the carrier gas. Therefore, the temperature of the tungsten wire in the measurement pool changes so that the resistance of the two tungsten wire in the two holes has a difference. This difference is measured by the bridge, and thus the content of the component to be measured.

The radioactive source in the testing room emits beta rays (primary electrons), which collide with the carrier gas in the testing room to produce secondary electrons and positive ions. On the effect of the electric field, they move to the electrode opposite to their polarity, forming a DC. When the electronegative component (that is, the component that can capture electrons) enters the testing chamber, it captures the electrons in the testing chamber and becomes negatively charged ions. Because the electrons are captured by the component, the base current in the testing chamber is reduced and the chromatographic peak signal is generated.

The components were separated by gas chromatography and then ionized, and the ionic mass of each component was measured.