A temperature programmed reaction/single-photon ionization time-of-flight mass spectrometry system for rapid investigation of gas-solid heterogeneous catalytic reactions under realistic reaction conditions

A Temperature-Programmed Reaction (TPRn)/Single-Photon Ionization Time-of-Flight Mass Spectrometry (SPI-TOF-MS) system is described. The TPRn/SPI-TOF-MS system allows rapid characterization of heterogeneous catalytic reactions under realistic reaction conditions and at the same time allows for the description of the reaction schemes

Coupling of stir bar sorptive extraction with single photon ionization mass spectrometry for determination of volatile organic compounds in water

A home-made stir bar sorptive extraction (SBSE) apparatus was combined to a single photon ionization time-of-flight mass spectrometer (SPI-TOFMS) for rapid and sensitive determination of trace volatile organic compounds (VOCs) in water. The home-made SBSE bar, low-cost and disposable, was used for VOCs extraction. A thermal desorption (TD) device was designed to desorb the analytes from the SBSE bar, and a high throughput interface was developed to transfer the analytes into the ionization chamber of the SPI-TOFMS. The combination of large extraction volume of SBSE bar, and the direct measurement power of SPI-TOFMS enable a short analysis time for VOCs in water with high sensitivity, for example the limits of detection (LODs) were in the range of 7.4-11.1 ng L-1 for benzene, toluene, and p-xylene (BTX) within 15 min. BTX aqueous solutions were chosen to demonstrate the quantitative capability, the linear range was from 0.05 to 100 mu g L-1 and the correlation coefficients were better than 0.996. The proposed method was successfully applied for the analysis of VOCs in urban river water

Distribution of toxic chemicals in particles of various sizes from mainstream cigarette smoke

<p>To accurately estimate the risk of inhaling cigarette smoke containing toxic chemicals, it is important that the distribution of these chemicals is accurately measured in cigarette smoke aerosol particles of various sizes. In this study, a single-channel smoking machine was directly coupled to an electrical low-pressure impactor. The particles of mainstream cigarette smoke were collected using 12 polyester films, and the particulate matter (PM) was characterized. Nicotine, tobacco-specific N-nitrosamines (TSNAs, including NNN, NAT, NAB, and NNK), polycyclic aromatic hydrocarbons (PAHs, including benzo(a)pyrene (BaP), benzo(a)anthracene, and chrysene), and heavy metals (including Cr, As, Cd, and Pb) present in the particles of different sizes were analyzed by GC, HPLC-MS/MS, GC/MS, or ICP-MS, respectively. The results demonstrated that the nicotine, TSNAs, PAHs, and heavy metals in mainstream cigarette smoke were dispersed over a particle size ranging from 0.1 μm to 2.0 μm, and the concentration of these toxic chemicals initially increased and then decreased the particle size grew. The distribution of nicotine was uniform for the PM in the size ranges of less than 0.1 μm, 0.1–1.0 μm, and 1.0–2.0 μm, TSNAs and heavy metals in particles of less 0.1 μm were more abundant, and PAHs in fine particles were also more abundant.</p