Development of a Portable Single Photon Ionization-Photoelectron Ionization Time-of-Flight Mass Spectrometer

Abstract

A vacuum ultraviolet lamp based single photon ionization- (SPI-) photoelectron ionization (PEI) portable reflecting time-of-flight mass spectrometer (TOFMS) was designed for online monitoring gas samples. It has a dual mode ionization source: SPI for analyte with ionization energy (IE) below 10.6 eV and PEI for IE higher than 10.6 eV. Two kinds of sampling inlets, a capillary inlet and a membrane inlet, are utilized for high concentration and trace volatile organic compounds, respectively. A mass resolution of 1100 at m/z 64 has been obtained with a total size of 40 × 31 × 29 cm, the weight is 27 kg, and the power consumption is only 70 W. A mixture of benzene, toluene, and xylene (BTX), SO2, and discharging products of SF6 were used to test its performance, and the result showed that the limit of quantitation for BTX is as low as 5 ppbv (S/N = 10 : 1) with linear dynamic ranges greater than four orders of magnitude. The portable TOFMS was also evaluated by analyzing volatile organic compounds from wine and decomposition products of SF6 inside of a gas-insulated switchgear.

Portable mass spectrometry system: instrumentation, applications, and path to ‘omics analysis

“…Huang et al. [52] combined VUV lamp‐based SPI with photoelectron ionization (PEI) for a portable time‐of‐flight (TOF) mass spectrometer for online gas monitoring. The combined ion source was able to ionize analytes having a large range of ionization energy.…”

Development of a suitcase time‐of‐flight mass spectrometer for in situ fault diagnosis of SF6‐insulated switchgear by detection of decomposition products

“…Power consumption is approximately 70 W at normal working conditions. The mass analyzer of the suitcase TOFMS is the same as the previously reported portable TOFMS, [26] but we modified the sampling inlet, ion source, and vacuum pumping system to satisfy the detection of the decomposition products inside of the GIS in this version.…”

Point-of-care detection of sevoflurane anesthetics in exhaled breath using a miniature TOFMS for diagnosis of postoperative agitation symptoms in children

“…In this study, based on the miniature TOFMS [32][33][34] developed in our laboratory, we optimized the experimental conditions of the magnetic field enhanced photoelectron ionization (MEPEI) 35,36 and established the quantitative curve and quantitative stability of sevoflurane. The MEPEI-TOFMS was used to monitor the concentration of sevoflurane in the exhaled breath of child patients during the operation and the recovery period in the clinical room.…”