What are the basic components of a gas chromatograph?
What are the components of a gas chromatograph?
The basic structure of a gas chromatograph consists of an analysis unit and a display unit. The former mainly includes gas source and control metering device, sampling device, constant temperature device and chromatographic column. The latter mainly includes the verifier and automatic recorder. The chromatographic column (including the stationary phase) and calibration products are the core components of the gas chromatograph.
(1)Carrier gas systemThe gas path in the gas chromatograph is a closed piping system in which the carrier gas runs continuously. The whole carrier gas system requires pure carrier gas, good gas tightness, stable flow rate, accurate flow measurement.
(2) The injection system is to add gas or liquid samples quickly and quantitatively to the top of the column.
(3)Separation systemThe core of the separation system is the chromatographic column, which is used to separate multi-component samples into single components. There are two types of columns:packed columns and capillary columns.
(4)The detector of the detection system is used to convert the sample components separated from the column into electrical signals according to their characteristics and content, which are amplified and recorded into a chromatogram by a recorder.
(5)Signal recording or computer data processing systemIn recent years, gas chromatographs mainly use chromatographic data processor. Chromatographic data processor can print and record the chromatogram, and can print the processed results, such as retention time, mass fraction of the measured component, etc.. on the same recording paper.
(6) The temperature control system is used to control and measure the temperature of the column, detector and gasification chamber, and is an important part of the gas chromatograph. There are two types of gas chromatographs:one is gas-solid chromatograph and the other is gas-liquid partition chromatograph. The two chromatographs separate different stationary phases, but the instrument structure is the same.