Title: | Recent advances in thermal desorption-gas chromatography-mass spectrometery method to eliminate the matrix effect between air and water samples: application to the accurate determination of Henry's law constant |
Address: | "Department of Civil and Environmental Engineering, Hanyang University, 222 Wangsimni-Ro, Seoul 133-791, South Korea. Department of Civil and Environmental Engineering, Hanyang University, 222 Wangsimni-Ro, Seoul 133-791, South Korea. Electronic address: kkim61@hanyang.ac.kr" |
DOI: | 10.1016/j.chroma.2014.03.040 |
ISSN/ISBN: | 1873-3778 (Electronic) 0021-9673 (Linking) |
Abstract: | "Accurate values for the Henry's law constants are essential to describe the environmental dynamics of a solute, but substantial errors are recognized in many reported data due to practical difficulties in measuring solubility and/or vapor pressure. Despite such awareness, validation of experimental approaches has scarcely been made. An experimental approach based on thermal desorption-gas chromatography-mass spectrometery (TD-GC-MS) method was developed to concurrently allow the accurate determination of target compounds from the headspace and aqueous samples in closed equilibrated system. The analysis of six aromatics and eight non-aromatic oxygenates was then carried out in a static headspace mode. An estimation of the potential bias and mass balance (i.e., sum of mass measured individually from gas and liquid phases vs. the mass initially added to the system) demonstrates compound-specific phase dependency so that the best results are obtained by aqueous (less soluble aromatics) and headspace analysis (more soluble non-aromatics). Accordingly, we were able to point to the possible sources of biases in previous studies and provide the best estimates for the Henry's constants (Matm(-1)): benzene (0.17), toluene (0.15), p-xylene (0.13), m-xylene (0.13), o-xylene (0.19), styrene (0.27); propionaldehyde (9.26), butyraldehyde (6.19), isovaleraldehyde (2.14), n-valeraldehyde (3.98), methyl ethyl ketone (10.5), methyl isobutyl ketone (3.93), n-butyl acetate (2.41), and isobutyl alcohol (22.2)" |
Keywords: | *Air Alcohols/chemistry Aldehydes/chemistry Benzene Derivatives/chemistry Esters/chemistry Gas Chromatography-Mass Spectrometry/*methods Gases Ketones/chemistry Molecular Weight Solubility Vapor Pressure *Water Equilibrium partitioning in closed systems H; |
Notes: | "MedlineKim, Yong-Hyun Kim, Ki-Hyun eng Research Support, Non-U.S. Gov't Netherlands 2014/04/08 J Chromatogr A. 2014 May 16; 1342:78-85. doi: 10.1016/j.chroma.2014.03.040. Epub 2014 Mar 21" |