thermal analyzerIt is a sample pretreatment device. The minimum concentration of organic compounds detected by GC or GC/MS can reach ppb or even ppt level. The thermal analyzer is a new type of thermal analyzer. Its advantages are that the recovery rate is close to 100 and the minimum detection limit is greatly reduced, thus ensuring the linear range, precision and accuracy of analysis.

Thermal analysis sampling technology is to put the solid sample or adsorption tube that adsorbs the analyte into the thermal analysis device and directly connect with the chromatograph (there are also independent installation models). The carrier gas enters the sampling port of the chromatograph through the thermal analysis device. When the temperature of the thermal analysis device rises, the volatile components are released from the solid sample or adsorbent, and enter the gas chromatography system together with the carrier gas for analysis and determination. Therefore, thermal analysis sampling can be considered as part of purge and trap sampling.

According to the national standard, the detection of benzene and TVOC in indoor ambient air should be carried out through thermal analysis. Specifically, when analyzing air pollutants, an adsorption tube equipped with an adsorbent (activated carbon or Tenax) is used to extract a certain amount of air with an atmospheric sampler. Through the adsorption tube, the pollutants in the air are adsorbed by the adsorbent in the tube. Then the adsorption tube is placed on the thermal analysis device. After analysis, the sample is injected with a syringe or connected to a gas chromatograph. After thermal analysis, the sample is directly injected for analysis.

The thermal analyzer can be an independent thermal analyzer not connected to the chromatograph, or it can be analyzed by the trap tube heating device of the purge and trap sampler. In this case, the thermal analyzer is a special case of purge and trap sampling, and the thermal analyzer can also be directly installed at the inlet of the chromatograph, which can become a special case of the pyrolysis sampler.