Dimerization Products of Chloroprene are Background Contaminants Emitted from ALTEF (Polyvinylidene Difhioride) Gas Sampling Bags

Abstract

Gas sampling bags have been used for collecting air samples. Tedlar bags are most commonly used, but bleed background chemicals such as N,N-dimethylacetamide and phenol. It is often necessary to remove the contaminant by flushing the bags with pure nitrogen or air. In this study, we identified four chloroprene dimerization products as background contaminants emitted from ALTEF bags that are made of a proprietary polyvinylidene difluoride (PVDF). No monomer chloroprene was detected in the bags analyzed. All of the dimers gradually increased once bags were filled with nitrogen due to diffusion from the bag surface. Flushing the bags with nitrogen reduced their concentrations, but was not effective for removing the contaminants. When the bags that had been flushed with nitrogen 5 times were left for 24 h, they increased again, indicating that the dimers were constantly emitted from the ALTEF bag surface. To our knowledge, these compounds have never been demonstrated in ALTEF or other PVDF bags. Our finding indicates that ALTEF might be incorporated with Neoprene (chloroprene-based polymer) during its manufacturing process.

Impact of thermal desorption tubes on the variability of exhaled breath data

“…While blank injections are often run during analyses to ensure a lack of carryover in the analytical system, addressing compounds found in the blank injections, i.e., subtraction or removal, has not yet been standardized for exhaled breath. Based on the tentative identifications provided in supplemental data 3 and 4 representing blank Tenax TA and Biomonitoring 5TD tubes, greater than 59% (16/27) of the compounds have been reported in the breath literature indicating the compounds were considered as potential targets in the studies [27,28]. While it is possible for these compounds to be greater than the background in exhaled breath, such as is often the case with acetone, most breath VOCs are in trace amounts and background could significantly impact the results and reporting.…”

Identifying VOCs in exhibition cases and efflorescence on museum objects exhibited at Smithsonian’s National Museum of the American Indian-New York

“…6 and Table 1). These products have been classified as dimerization products of chloroprene (2-chloro-1,3-butadiene), a monomer used during the production of rubber materials [28]. Chloroprene can polymerize spontaneously at room temperature in a process catalyzed by light, peroxides, and other free-radical initiators, generating the three compounds identified (among others).…”

Volatile compounds released by Nalophan; implications for selected ion flow tube mass spectrometry and other chemical ionisation mass spectrometry analytical methods

“…The breath sampling procedure is a critical step, as is the preservation of the sample integrity during storage, especially so into polymer bags . Surface adsorption of analytes, desorption of impurities and permeation/diffusion through the bag material in both directions can affect the composition of the sample . Chemical reactions facilitated by high sample humidity can also occur, especially for long storage times .…”

“…It is very robust, but comparatively expensive and releases N , N ‐dimethyl acetamide and phenol into the breath sample, which results from the use of solvents during its production Teflon (PTFE, polytetrafluoroethylene) and ALTEF bags are more inert but not very robust and also costly, which inhibits one‐time use Metal‐coated multilayer bags (Flexfoil, polyester aluminium, PEA, or Mylar) comprise a polymer layer combined with metallic film layers to reduce diffusion and permeation .…”