The effect of treating air samples with magnesium perchlorate for water removal during analysis for non-methane hydrocarbons
✍ Scribed by Doskey, Paul V.
- Publisher
- John Wiley and Sons
- Year
- 1991
- Tongue
- English
- Weight
- 471 KB
- Volume
- 14
- Category
- Article
- ISSN
- 0935-6304
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✦ Synopsis
Abstract
A comparison has been made between two cryogenic preconcentration ‐ high resolution gas chromatography techniques for the analysis of non‐methane hydrocarbons in ambient air, one involving treatment of air samples with magnesium perchlorate to remove water, the other involving analysis without treatment. Recoveries of C~1~‐, C~2~‐, and C~3~‐substituted benzenes in treated samples were 80%, 50%, and 50%, respectively. Incomplete recovery of C~7~‐C~9~ n‐1‐olefins was also observed. C~2~‐C~8~ hydrocarbons and C~2~‐C~6~ n‐1‐olefins were recovered with greater than 90% efficiency. Analyses of certified audit samples containing a mixture of C~2~‐C~8~ aliphatic and aromatic hydrocarbons at the 20 ppbv level in humidified zero‐grade air indicated that the accuracy of the technique for untreated air samples was approximately 90%. The use of magnesium perchlorate for water removal cannot be recommended for the analysis of non‐methane hydrocarbons in ambient air.