Evaluation of potential sample contamination from a self-designed automatic device for volatile organic compounds...

Area of Science:

• Environmental Science
• Analytical Chemistry

Background:

• Active sampling is crucial for monitoring volatile organic compounds (VOCs).
• Sampling strategies must ensure representativeness, ease of use, and prevent degradation, loss, or contamination.
• Self-designed active samplers utilizing sorbent tubes were developed for VOC collection.

Purpose of the Study:

• To evaluate potential contamination from different valve types used in active VOC sampling.
• To identify valve materials that minimize VOC contamination during sampling and storage.

Main Methods:

• Three valve types (two non-return, one solenoid) were tested for VOC diffusion contamination.
• Sorbent tubes were connected to valves for 15 days in an office environment.
• Blank tubes were used to assess background contamination levels.

Main Results:

• Non-return valves #1 and #2 leached significant amounts of aromatic hydrocarbons, ethers, and siloxanes.
• Solenoid valves exhibited minimal contamination, with VOC profiles similar to blank tubes.
• Contamination from non-return valves included specific ranges of ng per tube for different compound classes.

Conclusions:

• Non-return valves are a source of contamination in active VOC sampling devices.
• Solenoid valves are preferable for active VOC sampling due to their low contamination profile.
• Careful selection of sampling components is essential for accurate VOC monitoring.