艾条挥发性组分随温度升高释放规律的研究

Release rule of volatile components of moxa sticks with increase of temperature

目的:系统考察艾条在不同顶空温度及燃烧条件下释放出的挥发组分组成及其主要组分的变化规律,指导临床合理选择艾条的使用温度。方法:采用顶空-气相色谱质谱联用技术(HS-GCMS),将艾条置于顶空温度为室温(25℃)至190℃及艾条燃烧条件下,收集其释放出的气体,取其1 mL注入6890/5973N型气相色谱质谱联用仪(GCMS)。通过总离子色谱图(TIC)及丁酮内标法,计算艾条挥发性组分释放率;通过分析各挥发性组分的质谱图以及进行Nist 14标准质谱库匹配,定性分析各艾条挥发性组分;通过对比分析1,8-桉树脑及主要有害成分苯、甲苯、苯酚在不同顶空温度及燃烧条件下峰强度的变化规律,找出临床利用艾条的最佳温度。结果:室温和50℃时,艾条挥发性组分释放率很低,并随温度升高呈显著增加趋势,在顶空温度为190℃时,艾条挥发性组分释放率达0.864 2%,约为室温下的2 161倍,燃烧后其陡降至0.027 9%,比顶空温度190℃时降低了96.8%。在顶空温度为125℃及150℃时,艾条挥发性组分中典型有益成分1,8-桉树脑的含量最高,当顶空温度高于150℃时,其含量呈显著降低趋势。在燃烧条件下,检测到大量对人体有害的物质如苯、甲苯、苯酚等。结论:燃烧条件下不利于艾条挥发油的高效利用,125~150℃为艾条挥发性组分最佳的释放温度,既有利于艾条有益挥发性组分的释放,又能较大程度抑制有害成分的产生。

Objective To systematically investigate the changes rule of volatile oil and its main components released from moxa sticks under different headspace temperatures and combustion conditions, so as to guide the clinical rational selection of the temperature for moxa sticks. Methods Using the headspace gas chromatography-mass spectrometry(HS-GCMS) technique, the released gas from moxa sticks was collected at the headspace temperature(from room temperature [25 ℃] to 190 ℃) and during combustion. One m L of the gas was injected into 6890/5973N gas chromatography-mass spectrometry(GCMS). The release rates of volatile components of moxa sticks were calculated by total ion chromatography(TIC) and butanone internal standard method. The volatile components of moxa sticks were qualitatively analyzed by analyzing the mass spectra of each volatile component and matching the Nist 14 standard mass spectrometry library. By comparing and analyzing the peak intensity changes rule of 1,8-cineole and its main harmful components(benzene, toluene and phenol) under different headspace temperatures and combustion conditions, the optimal temperature for clinical use of moxa sticks was found. Results At room temperature and 50 ℃, the release rate of volatile components from moxa sticks was very low, and it showed a significant increase trend with the increase of temperature. When the headspace temperature was 190 ℃, the release rate of volatile components from moxa sticks reached 0.864 2%, which was 2 161 times as same as that at room temperature. After combustion, it dropped sharply to 0.027 9%, which was 96.8% lower than that at the headspace temperature of 190 ℃. When the headspace temperature was 125 ℃ and 150 ℃, the content of 1,8-cineole, a typical beneficial component in the volatile components of moxa sticks, was the highest. When the headspace temperature was higher than 150 ℃, its content showed a significant downward trend. Under combustion conditions, a large number of harmful substances, such as benzene, toluene and phenol, were detected. Conclusion The combustion condition is not conducive to the efficient utilization of the volatile oil of moxa sticks. Temperature of 125-150 ℃ is the best for releasing the volatile components of moxa sticks, which is not only conducive to the release of the beneficial volatile components of moxa sticks, but also can greatly inhibit the production of harmful components.