Purge and trapThe analysis method is to use inert gas to pass into the liquid sample (or solid surface), purge the components to be analyzed, enrich them through a container containing adsorbent, and then heat the adsorbent to desorb the adsorbed components, and carry them into the gas chromatography column for analysis. Widely used in environmental analysis, such as the analysis of organic pollutants in drinking water or wastewater. It is also used for the analysis of volatiles (such as odor components) in food.

The characteristics of purge and trap analysis method: it is suitable for extracting volatile or semi-volatile organic compounds with boiling point lower than 200 ℃ and solubility less than 2% from liquid or solid samples. It has the function of enrichment and is beneficial to the analysis of trace components. The pretreatment of the sample does not need to use organic solvents, does not cause secondary pollution to the environment, and has the advantages of less sampling, high enrichment efficiency, less interference by the matrix and easy to realize online detection. But easy to form foam, so that the instrument overload. And the use of more time, purging may introduce impurities and adsorbent performance selection. In addition, water also has a quenching effect on the flame detector with the blowing out of water vapor.

Purge the trap. A syringe pump is used for sampling, helium/nitrogen is used as the purge gas, and it is bubbled into the sample solution. Under continuous air flow purging, volatile components in the sample escape with the purge gas and are concentrated through a trapping device equipped with adsorbent. After a certain purging time, close the purge gas and switch the six-way valve to connect the trapping pipe to the carrier gas path of GC, at the same time, the rapid heating of the trap tube to desorb the trapped sample components and then enter the GC with the carrier gas for analysis.

Features and main functions of automatic solid/liquid integrated purge and trap instrument:

1. Fully automatic one-button start, automatically complete the sample injection analysis, no personnel on duty

2. Can be used for drinking water, wastewater and soil and other types of solid and liquid samplesPurge and trap

3. Automatic leak detection and fault alarm sampling system sampling arm moving smooth, accurate, low noise

4. Touch screen control, rich and complete interface information, simple operation, parameter setting, real-time display of working status and running time

5. All temperature control links and devices can be individually controlled temperature

6.10 methods for editing, storage and call at any time, press the run button to automatically complete the sample analysis

7. Synchronously start the gas chromatography-mass spectrometry, data processing workstation, can also be used to start the external event program of the device.

8. The trap is separated from the purge tube blowback gas to reduce cross-contamination between samples.

9. The whole process of inert pipeline connection transmission, reduce pollution residue

10. The connection point between the six-way valve and the transmission pipeline is in the heating insulation box, and there is no transmission cold point, which ensures the integrity of the sample.

11. The water removal trap removes water vapor at the purge end, greatly reducing the influence of water vapor on GC and GC/MS