Short-term storability of volatile organic compounds in bag sampling systems under ambient conditions.
Environ Res
; 256: 119269, 2024 Sep 01.
Article
in En
| MEDLINE
| ID: mdl-38815720
ABSTRACT
Although bag sampling is a common quantification tool for volatile organic compounds (VOCs), it can serve as a major source of experimental bias, when storing even over a short duration (<24 h). To learn more about the reliability of the bag sampling method, the temporal stability of 27 VOCs (classified into five groups (i.e., aldehydes, nonpolar aromatic hydrocarbons, aliphatic carboxylic acids, phenol and methylphenols, and miscellaneous odorants) is assessed using poly-ester aluminum (PEA) bags at five intervals over a day (0.17, 1, 2, 6, and 24 h). In terms of reproducibility (e.g., relative standard error [RSEt, %]), nonpolar aromatic hydrocarbons (BTXS) exhibit the highest consistency (e.g., average RSE <1.55%). Considerable loss of VOCs is observed in the preparation of gaseous standards from a liquid phase standard when assessed by gas/liquid (G/L) ratio. Further, VOCs with lower molecular weights (e.g., propionaldehyde 77%-94.4%) and branched molecular structures (e.g., isovaleraldehyde 67.2%-78.9%) tend to have high G/L ratio (e.g., relative to valeraldehyde 55.1%-66%). The overall relative recovery (RR; %) values of VOCs indicate an exponential decrease over 24 h. BTXS maintain fairly good RR values (above 94.3% at all intervals), possibly due to the nonpolar structure with uniform distribution of π electrons. In contrast, indole and skatole show the least preservation after 24 h (e.g., RR4 values of 10.9% and 24.6%, respectively) due to their highly reactive characteristics. The storability of VOCs appears to be affected by a number of variables (e.g., molecular weight, presence of ethyl branch, and time e.g., R2 > 0.9). The results of this study offer valuable guidelines for the accurate quantification of VOC levels in air.
Key words
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Environmental Monitoring
/
Volatile Organic Compounds
Language:
En
Journal:
Environ Res
/
Environ. res
/
Environmental research
Year:
2024
Document type:
Article
Country of publication:
Países Bajos