GC-9560-PED plasma emission gas chromatograph

One Plasma emission detector（PED）：

1. Detector construction diagram

The ionization chamber material is a quartz cell, and high-frequency and high-intensity electromagnetic fields are applied at both ends of the quartz cell. The carrier gas carries the components separated by the chromatographic column into the quartz cell, and under the action of high-pressure and high-intensity electromagnetic fields, the carrier gas and components are ionized together to form plasma.

Different components emit light radiation of different wavelengths in plasma, which is filtered and converted into chromatographic signals through photoelectric conversion. The signals are proportional to the content of gas standard substance components.

2. Detector principle

When gas passes through a high-frequency and high-intensity electromagnetic field, it is broken down and discharged. Discharge generates a large number of electrons and ions. Under the action of an electric field, electrons obtain energy from the electric field and collide with surrounding atoms and molecules to transfer energy, which excites ionization and produces an electron avalanche. When some high-energy electrons pass through conductive channels in an avalanche, some excited state atoms and molecules will spontaneously emit. We obtain signals through these radiations.

3. Characteristics of the detector

1) High sensitivity (PPb level)

2) High practicality (universal detector)

3) High stability (the substance does not directly contact the electrode)

4) Solving the difficulties of other detectors (neon detection, oxygen argon separation)

5) Main peak shielding