Title: | Routine analysis of off-flavor compounds in water at sub-part-per-trillion level by large-volume injection GC/MS with programmable temperature vaporizing inlet |
Address: | "Centre for Advanced Water Technology, Singapore Utilities International, Singapore 637723. lfzhang@cawt.sui.com.sg" |
DOI: | 10.1016/j.watres.2005.11.048 |
ISSN/ISBN: | 0043-1354 (Print) 0043-1354 (Linking) |
Abstract: | "'Earthy-musty' off-flavor problem in water samples are due to organic compounds present at the sub-part-per-trillion level. Most of the developments in the analysis of tastes and odorous compounds focus on the extraction pre-concentration technique, with detection at picogram per liter level of the earthy-musty off-flavor compounds difficult to be achieved. The objective of this study is to develop a new method involving the large-volume injection (LVI) GC/MS via programmable temperature vaporizing (PTV) inlet and continuous liquid-liquid extraction, to attain analytical sensitivity equal to or better than olfactory sensitivity. Six 'earthy-musty' organic compounds, 2-methylisoborneol (MIB), geosmin, 2,4,6-trichloroanisole, 2,3,6-trichloroanisole, 2,3,4-trichloroanisole and 2,4,6-tribromoanisole, were used as probes for this study. It was found that LVI via PTV could greatly improve system sensitivity towards off-flavor compound detection. Variable instrument conditions and sample preparation conditions were studied in detail. This reliable and efficient method has been optimized and validated. The method detection limit were found to be from 35 to 70 pg/L for haloanisoles, 50 pg/L for geosmin and 0.34 ng/L for MIB, with relative standard deviation of calibration curve ranging from 4.7% to 15.1% and recovery ranging from 58% to 96%. This method has been successfully applied to test off-flavor compounds in different types of water samples with satisfactory results" |
Keywords: | Calibration Environmental Monitoring/*methods Gas Chromatography-Mass Spectrometry/methods Organic Chemicals/analysis Sensitivity and Specificity Taste Temperature Volatilization Water Supply/*standards; |
Notes: | "MedlineZhang, Lifeng Hu, Ruikang Yang, Zhaoguang eng Evaluation Study England 2006/02/07 Water Res. 2006 Feb; 40(4):699-709. doi: 10.1016/j.watres.2005.11.048. Epub 2006 Feb 3" |