Single photon ionization and chemical ionization combined ion source based on a vacuum ultraviolet lamp for orthogonal acceleration time-of-flight mass spectrometry.
Single photon ionization and chemical ionization combined ion source based on a vacuum ultraviolet lamp for orthogonal acceleration time-of-flight mass spectrometry.
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DOI：
10.1021/ac200742r
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发表时间：
2011-06
影响因子：
7.4
通讯作者：
Lei Hua;Qinghao Wu;Keyong Hou;Huapeng Cui;Ping Chen;Weiguo Wang;Jinghua Li;Haiyang Li
中科院分区：
文献类型：
--
作者：
Lei Hua;Qinghao Wu;Keyong Hou;Huapeng Cui;Ping Chen;Weiguo Wang;Jinghua Li;Haiyang Li
研制了一种基于真空紫外灯的新型组合离子源，用于正交加速飞行时间质谱仪（oaTOFMS），该离子源同时具有单光子电离（SPI）和化学电离（CI）功能。SPI是使用商业10.6 eV氪放电灯实现的，光子通量约为10（11）光子s（-1），而CI是通过与O（2）（+）反应物离子的离子-分子反应实现的，所述O（2）（+）反应物离子是在中等真空压力（MVP）下通过光电子电离产生的。为了实现高的电离效率，离子源的压力提高到0.3毫巴和光电离长度延长到36毫米。因此，检测限（LOD）下降到3，4，和6 ppbv的苯，甲苯，和对二甲苯在MVP-SPI模式，和值分别为8和10 ppbv的甲苯和氯仿，分别在SPI-CI模式。由于该系统可以在MVP-SPI模式和SPI-CI模式之间快速切换，因此该系统能够监测具有宽范围电离能（IE）的复杂有机混合物。该系统的分析能力，通过测量长链烷烃的脱氢产物，烯烃通过直接毛细管采样和饮用水消毒副产物氯通过膜接口证明。
A novel combined ion source based on a vacuum ultraviolet (VUV) lamp with both single photon ionization (SPI) and chemical ionization (CI) capabilities has been developed for an orthogonal acceleration time-of-flight mass spectrometer (oaTOFMS). The SPI was accomplished using a commercial 10.6 eV krypton discharge lamp with a photon flux of about 10(11) photons s(-1), while the CI was achieved through ion-molecule reactions with O(2)(+) reactant ions generated by photoelectron ionization at medium vacuum pressure (MVP). To achieve high ionization efficiency, the ion source pressure was elevated to 0.3 mbar and the photoionization length was extended to 36 mm. As a result, limits of detection (LODs) down to 3, 4, and 6 ppbv were obtained for benzene, toluene, and p-xylene in MVP-SPI mode, and values of 8 and 10 ppbv were obtained for toluene and chloroform, respectively, in SPI-CI mode. As it is feasible to switch between MVP-SPI mode and SPI-CI mode rapidly, this system is capable of monitoring complex organic mixtures with a wide range of ionization energies (IEs). The analytical capacity of this system was demonstrated by measuring dehydrogenation products of long-chain paraffins to olefins through direct capillary sampling and drinking water disinfection byproducts from chlorine through a membrane interface.