Purge and trap instrument can automatically and accurately sample the liquid sample to the purge tube, the trap adsorption analysis of substances, can also be in distilled water after shaking, filtering, the solid sample is added to distilled water, purging collection.

Daily use:

Turn on the power switch, check whether the time and temperature settings are correct, and then wait for the meter to heat up to the set value.

Purge the trap and inject a proper amount of liquid sample. When the temperature reaches the set value, start the purging and collection process according to the user's own needs. The reference time is: dry blowing for 2 minutes, purging for 11 minutes, desorption for 1 minute, sample injection for 40 seconds, liquid discharge for 1 minute, and backblowing for 10-20 minutes.

Precautions for use:

1. Purge and capture should take into account purge efficiency and capture efficiency. It is difficult to purge the extraction of components, which can increase the total amount of purge gas and improve the purge efficiency. When the purge gas flow is unchanged, the purge time can be increased and the recovery rate can be improved. Increasing the amount of purge gas can increase the purge rate of gases with boiling points below 35°C, but due to the increase in the flow of purge gas, these gases will pass through the trap well, reducing the collection efficiency. The influence of cleaning gas volume and cleaning time should be considered comprehensively, and the recovery rate of each purging component should be taken into account.

2. The adsorption efficiency and the component to be measured and the adsorbent, such as the vapor pressure of the component. Surface area of adsorbent. Interaction between components and adsorbents, etc. In general, the trapping effect of the adsorbent on each component will be improved. In order to avoid the penetration of the absorption tube, the capture temperature should be 25 ℃ ± 2 ℃, below 30 ℃ is appropriate. Sometimes it is necessary to have a cooling device to capture some compounds at room temperature.

3. Purge and trap water removal methods are mainly osmosis and condensation. The infiltration method is very effective in removing moisture and polar substances, but it cannot be removed by the infiltration method when determining polar substances such as ketones in a sample. Condensate method is a commonly used dehydration method, which does not affect the recycling of polar compounds.

4. In the process of purging and trapping, sample foaming will pollute the purging and trapping instrument. The application of anti-foaming agent can inhibit the foaming of the sample, but it also has a certain effect on the characteristics of the sample, which leads to the uncertainty of the analysis results. Filling inert glass microspheres in the purging airway can effectively prevent the sample from foaming. The use of foam plastic filter can not prevent the sample from foaming, and it is easy to introduce errors.