Premium
Bias of Tedlar Bags in the Measurement of Agricultural Odorants
Author(s) -
Trabue Steven L.,
Anhalt Jennifer C.,
Zahn James A.
Publication year - 2006
Publication title -
journal of environmental quality
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.888
H-Index - 171
eISSN - 1537-2537
pISSN - 0047-2425
DOI - 10.2134/jeq2005.0370
Subject(s) - olfactometry , odor , thermal desorption , chemistry , tenax , methanethiol , chromatography , skatole , gas chromatography , mass spectrometry , acetic acid , dimethyl trisulfide , gas chromatography–mass spectrometry , environmental chemistry , desorption , organic chemistry , adsorption , sulfur , indole test , dimethyl disulfide
Odor regulations typically specify the use of dynamic dilution olfactometery (DDO) as a method to quantify odor emissions, and Tedlar bags are the preferred holding container for grab samples. This study was conducted to determine if Tedlar bags affect the integrity of sampled air from animal operations. Air samples were collected simultaneously in both Tedlar bags and Tenax thermal desorption tubes. Sample sources originated from either a hydrocarbon‐free air tank, dynamic headspace chamber (DHC), or swine‐production facility, and were analyzed by gas chromatography–mass spectrometry–olfactometry (GC–MS–O). Several background contaminants were identified from Tedlar bags, which included the odorous compounds N , N ‐dimethyl acetamide (DMAC), acetic acid, and phenol. Samples from the DHC demonstrated that recovery of malodor compounds was dependent on residence time in the Tedlar bag with longer residence time leading to lower recovery. After 24 h of storage, recovery of C 3 –C 6 volatile fatty acids (VFA) averaged 64%, 4‐methylphenol and 4‐ethylphenol averaged 10%, and indole and 3‐methylindole were below the detection limits of GC–MS–O. The odor activity value (OAV) of grab samples collected in Tedlar bags were 33 to 65% lower following 24 h of storage. These results indicate that significant odorant bias occurs when using Tedlar bags for the sampling of odors from animal production facilities.