Improvement of the Determination of Aldehydes in Water

• Main Authors: Chang chun-ming, 張峻鳴
• Other Authors: Tsai shih-wei
• Format: Others
• Language: zh-TW
• Published: 2002
• Online Access: http://ndltd.ncl.edu.tw/handle/47351757820427890557

碩士 === 中國醫藥學院 === 環境醫學研究所 === 90 === In this study, PFBHA was first coated onto the polydimethylsiloxane/ divinylbenzene（PDMS/DVB）fiber by headspace SPME extraction. The adsorption profiles of different aldehydes standard solutions were then determined by the head space extraction under the use of magnetic stir. After sampling, the sampler was inserted into the injection port of gas chromatography/mass spectrometry (GC-MS) for thermal desorption and sample analysis. The equilibrium time for PFBHA coating onto PDMS/DVB fiber was 20 min (the maximum amounts of PFBHA can be adsorbed on the fiber). The desorption efficiency reached 99.98% when the sample was analyzed at 250°C for 2 min of thermal desorption. The equilibrium times for the aldehydes analyzed were all within 30 min based on the adsorption profiles, including propionaldehyde, butyraldehyde, and valeraldehyde while it was 80 min for formaldehyde. The method detection limits were lower than 3 μg/L. The precision were lower than 10％. The accuracy were in the range of 95~122％（except for formaldehyde）. The analytical method in this study combined the use of PFBHA and SPME technique to determine the aldehydes in water. It has the advantages of solvent-free, short extraction time and high reproducibility over the current methods. The use of GC-MS for oximes analysis (formed by PFBHA reacting with aldehydes) increased the possibility of qualitative analysis of unknown samples as well as the analytical sensitivities. More studies will be needed to determine if the method can also be applied to the analysis of ketones in water.