| Summary: | 碩士 === 國立中興大學 === 化學系所 === 96 === This study was evaluated to determine trace seven nitrated polycyclic aromatic hydrocarbons (NPAHs) in aqueous solution by using purge assisted headspace solid phase microextraction (PA-HS-SPME) combined with gas chromatography/mass spectrometry in negative ion chemical ionization (GC/NICI-MS). The proposed method was based on continuous purging gas through the sample to carry analytes to headspace in which a SPME fiber was used as sorptive device. The parameters affecting the extract efficiency such as SPME fiber, extraction temperature, extraction time, agitation rate, salt effect, pH, hollow fiber length, and nitrogen flow rate were systematically studied. Compared to HS-SPME, PA-HS-SPME provides a significantly improved sensitivity for the extraction of NPAHs, especially for less-volatile NPAHs which could not be detected by HS-SPME. The linear range was 5 - 5000 pg/mL with correlation coefficients above 0.996. Limits of detection (LOD) of seven NPAHs were in the range of 0.01 to 0.10 pg/mL. The application of the methods to the determination of NPAHs in real samples was tested by analyzing aqueous samples from rivers in Taichung city.
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