Portable gas chromatography-mass spectrometry (GC-MS) is a high-precision analytical instrument that combines gas chromatography (GC) and mass spectrometry (MS) technologies. It has the characteristics of high sensitivity, high resolution, and rapid analysis, and is widely used in environmental monitoring, food safety, chemical analysis, and other fields.

　　Portable gas chromatography-mass spectrometerThe working principle of is to combine two independent analytical techniques, gas chromatography and mass spectrometry, to separate the chemical components in the sample through gas chromatography, and then perform qualitative and quantitative analysis on the separated components through a mass spectrometer. The specific principle is as follows:

1、 Gas chromatography section (GC)

Gas chromatography uses gas as the mobile phase and utilizes the different physical or chemical properties of the stationary phase to separate different components in the sample according to their distribution coefficients in the stationary phase. Gas chromatography consists of a sample injection system, separation column, carrier gas, temperature control system, etc. After the sample is injected into the injection port, it enters the separation column together with the carrier gas. Through the interaction between different substances and the stationary phase in the column, it is gradually separated according to differences in molecular size, polarity, boiling point, etc. Finally, the separated components are detected by a mass spectrometer through the end of the chromatographic column.

2、 Mass spectrometry section (MS)

Mass spectrometry is the analysis of substances by measuring the mass and charge ratio (m/z) of particles (mainly ions). In a portable gas chromatography-mass spectrometer, the various components separated by gas chromatography enter and are converted into ions by an electron bombardment source. These ions are accelerated, focused, and separated by a mass analyzer before being detected by a detector. By measuring the mass and abundance of different ions, mass spectrometers can help analyze the structural information, molecular weight, and content of different components.

3、 Joint system

Data exchange and coordination between gas chromatography and mass spectrometry in a combined system. The sample is first separated by gas chromatography, and the separated components are sequentially entered into a mass spectrometry analysis system for precise qualitative and quantitative analysis. The advantage of combined technology lies in its ability to accurately identify trace components in complex samples by combining the high resolution of gas chromatography with the high sensitivity of mass spectrometry.

Portable gas chromatography-mass spectrometry (GC-MS) has shown wide application prospects in multiple fields due to its characteristics of miniaturization, high sensitivity, and real-time analysis. With the continuous development of technology, its performance and application scenarios will continue to expand, becoming an important tool for rapid on-site detection and emergency response.