醛类污染物的二溴甲烷质子化增强检测  

Protonation-enhanced sensitive detection of aldehydes via dibromomethane doping

作　　者：许策[1,2] 李震 张海旭[1,2] 束继年 

机构地区：[1]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,北京100085 [2]中国科学院大学,北京100049

出　　处：《环境化学》2017年第12期2523-2530,共8页Environmental Chemistry

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~~

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.Low-pressure photoionization（LPPI） is a new soft ionization technique working under the pressure of hundreds to thousands Pa.Coupled with a mass spectrometer,LPPI presents superior sensitivity compared with other ionization methods.However,limited by the photoionization crosssections of analytes,the sensitivity of LPPI-MS to aldehydes is not sufficient.In this paper,acetaldehyde（261.8 μg · m^（-3））,propionaldehyde（666.7 μg · m^（-3）） and butylaldehyde（653.4 μg·m^（-3）） were used as samples.The influences of doped dibromomethane on LPPI of aldehydes were investigated.The experimental results revealed that the signal intensity of the protonated aldehydes increased with the amount of doped dibromomethane.The signal intensity of acetaldehyde,propionaldehyde and butylaldehyde reached the maximum when the dibromomethane concentrations of 1225.9,1016.4,and 721.6 mg·m^（-3） were doped respectively,with the signal intensity enhanced by 33,60 and 21 times.The detection sensitivity for acetaldehyde,propionaldehyde and butylaldehyde reached 230,146,and 105 counts·（μg·m^（-3））-1 correspondingly.These experimental results provide a new technique for the highly sensitive detection of aldehydes and other volatileorganic compounds（VOCs）.

关 键 词：低气压光电离 掺杂 醛类 二溴甲烷 质子化增强 

分 类 号：O657.63[理学—分析化学] X831[理学—化学]