Identification of control parameters for the sulfur gas storability with bag sampling methods
Sang-Hee Jo1, Ki-Hyun Kim, Zang-Ho Shon
1Department of Environment & Energy, Sejong University, Seoul 143-747, Republic of Korea.
Analytica Chimica Acta
|July 14, 2012
Summary
Storage stability of sulfur compounds in air samples depends on initial concentration and bag material. Reduced sulfur compounds showed better stability than oxidized sulfur dioxide (SO2), especially in polyvinyl fluoride (PVF) bags.
Area of Science:
- Environmental Chemistry
- Analytical Chemistry
- Atmospheric Science
Background:
- Air samples containing sulfur compounds require stable storage before analysis.
- Understanding storage stability is crucial for accurate environmental monitoring.
- Previous studies have not comprehensively evaluated sulfur compound stability across various conditions.
Purpose of the Study:
- To compare the storage stability of six gaseous sulfur compounds.
- To evaluate the influence of two bag materials (PVF and PEA) on storage stability.
- To assess the impact of five initial concentration levels (1-10,000 ppb) on stability.
Main Methods:
- Six sulfur compounds (H2S, CH3SH, DMS, CS2, DMDS, SO2) were stored in PVF and PEA bags.
- Initial concentrations ranged from 1 to 10,000 ppb.
- Gas chromatography-pulsed flame photometric detector (GC-PFPD) with an air server/thermal desorber system was used to determine response factors (RF) after 0, 1, and 3 days.
Main Results:
- Higher initial concentrations (1000-10,000 ppb) showed more rapid concentration reduction than lower levels (1-100 ppb).
- Storage stability was significantly influenced by initial concentration, bag material, and oxidation status.
- Oxidized sulfur dioxide (SO2) exhibited poor stability, nearly disappearing in PVF bags within one day, unlike reduced sulfur compounds (RSCs).
Conclusions:
- The storability of gaseous sulfur species is interactively determined by initial concentration, bag material, and oxidation state.
- Polyvinyl fluoride (PVF) bags are less suitable for storing oxidized sulfur compounds like SO2.
- Accurate analysis of sulfur compounds requires careful consideration of storage conditions, including material and concentration.
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