Quality control in quantification of volatile organic compounds analysed by thermal desorption-gas chromatography-mass spectrometry. J Chromatogr A 1186:348-357

Research Group EnVOC, Department of Organic Chemistry, Faculty of Bioscience Engineering, Ghent University, Coupure Links 653, B-9000 Ghent, Belgium.
Journal of Chromatography A (Impact Factor: 4.17). 05/2008; 1186(1-2):348-57. DOI: 10.1016/j.chroma.2007.11.036
Source: PubMed


This paper presents a detailed study on the calibration of a thermal desorption-gas chromatography-mass spectrometry (TD-GC-MS)-based methodology for quantification of volatile organic compounds (VOCs) in gaseous and liquid samples. For the first time, it is documented to what extent three widely encountered problems affect precise and accurate quantification, and solutions to improve calibration are proposed. The first issue deals with the limited precision in MS quantification, as exemplified by high relative standard deviations (up to 40%, n=5) on response factors of a set of 69 selected VOCs in a volatility range from 16 Pa to 85 kPa at 298 K. The addition of [(2)H(8)]toluene as an internal standard, in gaseous or liquid phase, improves this imprecision by a factor of 5. Second, the matrix in which the standard is dissolved is shown to be highly important towards calibration. Quantification of gaseous VOCs loaded on a sorbent tube using response factors obtained with liquid standards results in systematic deviations of 40-80%. Relative response factors determined by the analysis of sorbent tubes loaded with both analytes and [(2)H(8)]toluene from liquid phase are shown to offer a reliable alternative for quantification of airborne VOCs, without need for expensive and often hardly available gaseous standards. Third, a strategy is proposed involving the determination of a relative response factor being representative for a group of analytes with similar functionalities and electron impact fragmentation patterns. This group method approach indicates to be useful (RSD approximately 10%) for quantifying analytes belonging to that class but having no standards available.

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    • "This characterization is fundamental to further study on the mechanism of odorous gas formation and finally improve the operation of waste treatment system by controlling the odor formation and emissions. Efforts have been made during the last decades on qualitative and quantitative analysis of odorous compounds from different landfills, and Table 1 is the summary of these results (Brosseau and Heitz, 1994; Chiriac et al., 2007; Davoli et al., 2003; Deipser and Stegmann, 1994; Demeestere et al., 2008; Dincer et al., 2006; Fang et al., 2012). "
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    Waste Management 05/2015; 42. DOI:10.1016/j.wasman.2015.04.030 · 3.22 Impact Factor
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    • "For the quantitative analysis of highly volatile compounds, preparation of standards is an important part of performing accurate quantification. For this purpose, the use of a gaseous standard is a common option, as it allows the elimination or suppression of major experimental drawbacks (e.g., the matrix effect) encountered due to the phase difference between the sample (gas) and the standard phases (liquid) [10] [11]. However, the storage of diverse volatiles in gas phase may be complicated as sample integrity can degrade with time [12]. "
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    Journal of Chromatography A 12/2014; 1373:149-158. DOI:10.1016/j.chroma.2014.10.086 · 4.17 Impact Factor
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    • "Headspace of Tol-d 8 and n-alkanes (500 mL each) was loaded always into conditioned absorbent tubes before sampling. Description of preparation of the Tol-d 8 headspace as a closed two-phase system (CTS) can be found in Demeestere et al. (2008). Afterwards, the adsorption tubes were closed with Swagelok fitting, stored at room temperature and analyzed within 24 h. "
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