醛类污染物的二溴甲烷质子化增强检测

发布时间：2018-04-22 15:47

本文选题：低气压光电离 + 掺杂　；参考：《环境化学》2017年12期

【摘要】：低气压光电离(LPPI)是一种在数百到数千Pa的气压条件下工作的新型软电离技术,与质谱结合,检测灵敏度显著优于其他光电离形式,然而受到待测物分子自身电离截面的限制,LPPI-MS对醛类检测的灵敏度较低.本文以乙醛(261.8μg·m~(-3))、正丙醛(666.7μg·m~(-3))和正丁醛(653.4μg·m~(-3))为研究对象,研究了掺杂二溴甲烷对醛类低气压光电离过程的影响,发现在低二溴甲烷浓度条件下,醛类质子化信号随掺杂的二溴甲烷浓度增加而增加,当二溴甲烷浓度为1225.9、1016.4、721.6 mg·m~(-3)时,质子化的乙醛、正丙醛和正丁醛信号最高,此时,乙醛、正丙醛和正丁醛的信号分别提高33、60和21倍,相应的灵敏度达230、146、105 counts·(μg·m~(-3))~(-1).本文的研究结果为醛类及其它挥发性有机物(VOCs)的高灵敏度检测提供了新的技术方法.
[Abstract]:Low pressure photoionization (LPPI) is a new soft ionization technique operating under pressure conditions ranging from hundreds to thousands of Pa. Combined with mass spectrometry, the sensitivity of LPPI is significantly better than that of other forms of photoionization. However, the sensitivity of LPPI-MS to the detection of aldehydes is low due to the limitation of the self-ionization cross section of the molecules to be tested. In this paper, the effects of doped dibromomethane on the photoionization of aldehydes at low atmospheric pressure were studied with acetaldehyde (261.8 渭 g), n-propionaldehyde (666.7 渭 g) and n-butyraldehyde (653.4 渭 g). It was found that under the condition of low concentration of dibromomethane, the effect of dibromomethane on the photoionization process of aldehydes was studied. The protonation signal of aldehydes increased with the increase of the concentration of dibromomethane doped. When the concentration of dibromomethane was 1225.9n 1016.4721.6 mg / m ~ (-3), the signal of protonation of acetaldehyde, n-propionaldehyde and n-butyraldehyde was the highest. The signals of n-propionaldehyde and n-butyral were increased by 33U 60 and 21 times, respectively, and the corresponding sensitivity was 230146105 counts (渭 g / g). The results of this paper provide a new technical method for the high sensitivity detection of aldehydes and other volatile organic compounds (VOCs).
【作者单位】：环境模拟与污染控制国家重点联合实验室中国科学院生态环境研究中心;中国科学院大学;
【基金】：中国科学院大气灰霾追因与控制战略先导专项(XDB05040501)资助~~
【分类号】：O657.63;X831

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