Characterization of a Pressurized C5−C16 Hydrocarbon Gas Calibration Standard for Air Analysis

Autor:	Detlev Helmig, Tobias Revermann, B. D. Hall
Rok vydání:	2004
Předmět:	chemistry.chemical_classification Analyte Chromatography Chemistry Diffusion Condensation Analytical chemistry Mixing (process engineering) Analytical Chemistry Dilution chemistry.chemical_compound Hydrocarbon Gravimetric analysis Isoprene
Zdroj:	Analytical Chemistry. 76:6528-6534
ISSN:	1520-6882 0003-2700
DOI:	10.1021/ac049113h
Popis:	A compressed gas standard containing parts-per-billion (ppb) amounts of the volatile hydrocarbons methylpentadiene (isoprene, 540 ppb) and isooctane (259 ppb) and a series of less volatile C12-C16 n-alkanes (n-dodecane, 349 ppb; n-tridecane, 340 ppb; n-tetradecane, 202 ppb; n-pentadecane, 271 ppb; and n-hexadecane, 308 ppb) was prepared by a one-step (no further gas dilution) microgravimetric method. The gravimetric mixing ratios were confirmed by referencing to a capillary diffusion method. The cylinder was heated to 75 degrees C to minimize condensation losses of analytes to the cylinder walls. Mixing ratios were monitored over a 2.5-year period. Some initial analyte losses (approximately 3 to 20%) were observed for the heavier C14-C16 n-alkanes. Subsequently, analyte loss rates were found to be in the range of1.0% per year for n-dodecane to n-hexadecane. The developed guidelines for preparation, storage, and retrieval of these semivolatile analytes enable the use of compressed gas standards for calibration and method development purposes in the environmental gas-phase analysis of these and related compounds.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_dedup___::82b3462f462f6bcd06fdba334c181a8b https://doi.org/10.1021/ac049113h Zobrazit plný text záznamu