scholarly journals Eluent-assisted Nonresonant Multiphoton Ionization of Polycyclic Aromatic Hydrocarbons in a Liquid Chromatograph-mass Spectrometer

2018 ◽  
Vol 47 (8) ◽  
pp. 1014-1017
Author(s):  
Naoki Oya ◽  
Tomoyuki Yatsuhashi
2018 ◽  
Vol 41 (5) ◽  
Author(s):  
Ananias Francisco Dias Júnior ◽  
Carlos Rogério Andrade ◽  
José Otávio Brito ◽  
Simone Possedente Lira ◽  
Azarias Machado de Andrade ◽  
...  

ABSTRACT Charcoal is a widely used product for barbecue, however, its quality for said use has not been well studied. Polycyclic aromatic hydrocarbons (PAHs) are a class of carcinogenic compounds that can be present in charcoal. Thus, the objective of this study was to analyze the organic phase extracted from charcoal by organic solvents, regarding the presence of PAHs. For this, a commercial charcoal brand was acquired, collected in establishments in the city of Piracicaba, São Paulo. Complementary tests were carried out to identify the wood used in the production of charcoal, such as determination of humidity, apparent density, immediate composition, calorific value, and combustion index. The organic phase extracted from the charcoal using cyclohexane was analyzed in a gas chromatograph coupled to a mass spectrometer (GC/MS) for identification of a class of sixteen PAHs. In general, charcoal presented regular characteristics for barbecue. All PAHs analyzed were detected in the organic phase extracted from the charcoal, but the observed values were below the quantified limit determined


2014 ◽  
Vol 955-959 ◽  
pp. 1089-1092
Author(s):  
A Dan Li

Gas chromatography resonance-enhanced multiphoton ionization time-of-flight mass spectrometry (GC/REMPI-TOFMS) using a nanosecond laser has been applied to analyze the 16 polycyclic aromatic hydrocarbons (PAHs). The excited-state lifetime, absorption characters, energy of electronic states of the 16 PAHs were investigated to optimize the ionization yield. The results suggested that REMPI is superior to elctron impact ionization method for soft ionization, and suppresses the background signal caused by the aliphatic hydrocarbons. Thus, GC/REMPI-TOFMS is a more reliable method for the determination of PAHs present in the environment.


1982 ◽  
Vol 60 (19) ◽  
pp. 2484-2499 ◽  
Author(s):  
Robert K. Boyd ◽  
Bori Shushan

Unexpected correlations have been found between spectroscopic (uv and nmr) properties of some aromatic systems (specifically polycyclic aromatic hydrocarbons and chlorinated biphenyls) and fragmentation rates of the corresponding metastable molecular ions in a field-free region of a mass spectrometer. The meaning of these empirical correlations is explored via the quasi-equilibrium theory of mass spectra. For the case of the polycyclic aromatic hydrocarbons for which more complete ancillary data are available, a reasonably self-consistent account of the correlations can be obtained via the ionisation energy as the crucial parameter. The case of the chlorinated biphenyls is less clear, due to a lack of subsidiary data. However, the best explanation available appears to involve a systematic shift in the energy deposition function with increasing steric interaction around the biphenyl linkage.


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