Determination of acetone in human exhaled breath by Hadamard transform-gas chromatography/mass spectrometry
| Autor: | Chien-Lin Yang, 楊建霖 |
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| Rok vydání: | 2013 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 101 In this study, the Hadamard transform-gas chromatography/mass spectrometry (HT-GC/MS) technique was successfully employed for detecting of a trace of acetone from human exhaled breath. Experimental gas samples were collected from several diabetic patients and normal volunteers. A 100mL exhaled breath was collected from each subject, and the collected gases in gas sampling bags did not require any extraction procedure before measurement. Based on the Hadamard code’s electromagnetic valve controlled by the computer, the gas samples were sequentially injected into the GC/MS with the volume of 11 μL each. Under the optimized conditions, when the Hadamard matrices of 255, 511 and 2047 were used, the S/N ratios were substantially improved to 6.4-, 11.3-, and 20.9-fold, respectively, matched with those expected from theoretical values (8.0-, 11.3-, 22.6-fold). The measurement of a single sample could be completed within 3.5 minutes. This study also employed traditional headspace solid-phase microextraction (HS-SPME) for comparison. The result showed that when the extraction needle, model SU-57310U, was used, a single measurement could be completed within 4 minutes. According to medical reports, the acetone concentration in normal people’s exhaled breath is very low. This view was confirmed by the actual measurement of eight non-diabetic volunteers’ exhaled breath, 30 bags of gases in total, each of which was measured five times repeatedly, obtaining an average value of 0.1 to 1 ppmv. In this case, both HT and higher-cost SPME are effective in improving detection sensitivity. HT is suitable for various types of gas while SPME should choose the proper microextraction syringe depending on the detected gas type in order to achieve desired results. Besides, due to the higher concentration of acetone in the exhaled breath from diabetic patients used in this experiment, it could also be detected without employing HT or SPME. The actual measurement on the exhaled breath from four diabetic patients (including type I and type II), 30 bags of gases in total, each of which was measured 20 times repeatedly, obtained an average value of 1 to 10 ppmv. Keywords: Hadamard, acetone, gas chromatography/mass spectrometry |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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