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김미언,강지환,김용두,이동수,이상일 대한화학회 2018 Bulletin of the Korean Chemical Society Vol.39 No.3
Dimethyl sulfide (DMS) is a crucial precursor in the formation of aerosols that play important roles in climate change. Stable and traceable primary standard gas mixtures (PSMs) are critical for accurate measurement of the trace amounts of reactive DMS reported at sub-nanomole per mole (nmol/mol) levels at remote monitoring sites. However, the preparation of DMS at ambient levels in high-pressure cylinders is challenging because of its instability. This study examined the long-term stability of 0.5–7.0 nmol/mol DMS PSMs prepared in specially treated cylinders. Ten months after the PSM preparation, the DMS PSMs were compared with traceable dynamically diluted gas mixtures (DDMs). The DMS PSMs at 2–7 nmol/mol levels were stable for 10 months with uncertainties of less than 2.5% (k = 2). However, the amount-of-substance fraction (i.e., mole fraction) of the DMS PSM at 0.5 nmol/mol was 5.4% less than the gravimetrically determined mole fraction, which exceeds the uncertainty of 3.5%. These findings indicate that DMS PSMs at 2–7 nmol/mol levels are sufficiently stable for use as primary standards for long-term monitoring of trace-level DMS in remote areas, whereas DMS PSM at 0.5 nmol/mol is not sufficiently stable.
허귀석,김용두,유연미,김미언,전은주 한국냄새환경학회 2007 실내환경 및 냄새 학회지 Vol.6 No.4
Analytical methods for odorous butanol compound were developed using canister sampling method and solid adsorbent sampling method. Stability of butanol gas component was evaluated for enhancing accuracy of measurement and to avoid a problem of its poor stability due to its polar character. Quality control method of the analysis was also examined. Gaseous standard gas containing BuOHl and MEK was prepared using canister for evaluation of stability and analytical linearity. BuOH showed a poor stability and poor linearity compared to MEK. However, when the same VOC standard was prepared using adsorbent tube, the stability and linearity of BuOH were much better compared to canister method. Therefore, sampling for the measurement of BuOH in air using adsorbent tube can give better result compared to canister method.