Impact of Storage Conditions on the Stability of Volatile Sulfur Compounds in Sampling Bags

Odorous emissions from agricultural and waste management operations can cause annoyance to local populations. Volatile sulfur compounds (VSCs) are dominant odorants that are often lost during collection using sample bags. The degree of VSC losses depends on factors such as storage time, bag materials, temperature, sample relative humidity (RH), light exposure, and the presence of volatile organic compounds (VOCs). To assess the impact of those factors on the stability of 10 VSCs (hydrogen sulfide, methanethiol, ethanethiol, dimethyl sulfide, tert-butanethiol, ethyl methyl sulfide, 1-butanethiol, dimethyl disulfide, diethyl disulfide, and dimethyl trisulfide), laboratory-based experiments were conducted according to a factorial experimental design. Linear mixed-effects models were constructed for loss predictions. The estimated recovery of HS in Tedlar bag was 8 to 10% higher than in Mylar and Nalophan between 6 and 30 h. At ≤20°C and without being exposed to light, at least 75% relative recovery of the 10 VSCs in Tedlar bags can be achieved after 18 h, whereas, a maximum of 12 h of storage should not be exceeded to ensure a minimum of 74% relative recovery of the VSCs in Mylar and Nalophan bags.