Publications by authors named "Zitao Yan"

The real-time detection of gaseous HO and its typical isotopic molecules, e.g., HO, DO, HDO, and HTO, is highly desirable in many fundamental scientific studies and practical monitoring, such as mechanistic studies of HO-involved chemical reactions and radiation risk warning of abnormal HTO emissions.

View Article and Find Full Text PDF

Various vacuum ultraviolet (VUV) lamps are simple and convenient VUV light sources for mass spectrometry and other research fields. However, the strong absorption of high-energy photons by window materials limits the application of an extreme ultraviolet (EUV) light. In this study, a novel high-flux EUV light source is developed using a microchannel plate (MCP) window to transmit 73.

View Article and Find Full Text PDF

The secondary organic aerosol (SOA) yield of toluene photooxidation was reported to substantially higher than that of trimethylbenzene due to the effect of the number of methyl substituents. However, the intrinsic mechanism for this disparity is not clear enough. In this study, a highly-sensitive thermal-desorption photoinduced associative ionization mass spectrometer (TD-PAI-MS) was used to real-time characterize the molecular composition and its evolution of the SOA generated from the photooxidation of toluene and 1,2,3-trimethylbenzene (1,2,3-TMB) in a smog chamber.

View Article and Find Full Text PDF

Volatile organic compounds (VOCs) released along with soil disturbance during the remediation of abandoned industrial sites have attracted great attention due to their possible toxicity and odour. However, the real-time emission characteristics of these VOCs and their subsequent effects on health and olfaction are less understood. In this study, the gaseous VOCs released from soil disturbance by excavators and drilling rigs at an abandoned chemical pesticide plant were monitored online with a laboratory-built single photoionization time-of-flight mass spectrometer (SPI-TOFMS).

View Article and Find Full Text PDF

Single-photon ionization (SPI) is a unique soft ionization technique for organic analysis. A convenient high-flux vacuum ultraviolet (VUV) light source is a key precondition for wide application of SPI techniques. In this study, we present a novel VUV lamp by simply modifying an ordinary electrodeless fluorescent lamp.

View Article and Find Full Text PDF

Photoionization mass spectrometry (PI-MS) has become a versatile tool in the real-time analysis of volatile organic compounds (VOCs) from the atmosphere or exhaled breath. However, some key species, , acetonitrile, are hard to measure due to their higher ionization energies than photon energy. In this study, the direct and sensitive detection of gaseous acetonitrile based on a photoinduced associative ionization (PAI) reaction was investigated with a laboratory-built PAI time-of-flight mass spectrometer (PAI-TOFMS).

View Article and Find Full Text PDF