Polychlorinated Aromatic Hydrocarbons in a Soil Sample Measured Using Gas Chromatography/Multiphoton Ionization/Time-of-Flight Mass Spectrometry

Abstract

Gas chromatography/multiphoton ionization/time-of-flight mass spectrometry (GC/MPI/TOF-MS) was applied to a soil sample to survey several groups of polychlorinated aromatic hydrocarbons (polychlorinated dibenzo-p-dioxins/dibenzofurans (PCDD/Fs), polychlorinated biphenyls (PCBs), polychlorinated naphthalenes (PCNs), polychlorinated diphenylethers (PCDEs), and polychlorinated terphenyls (PCTs)). The signal peaks in the two-dimensional display of GC/MS could be easily and accurately assigned from the intensity distribution of the isotope peaks, even in the presence of numerous interfering species. Using this technology, mutual interferences between organochlorine compounds can be readily recognized from the data of the two-dimensional display after a measurement, although the separation of these compounds is sometimes difficult using high-resolution magnetic-sector-type mass spectrometry. This approach, based on MPI, results in less fragmentation, and is useful for the identification of analytes. Thus, GC/MPI/TOF-MS allows for the simultaneous determination of PCDD/Fs and related compounds in real samples containing numerous interfering species.

Analysis of Persistent Organic Pollutants at Sub-Femtogram Levels Using a High-Power Picosecond Laser for Multiphoton Ionization in Conjunction with Gas Chromatography/Time-of-Flight Mass Spectrometry

“…Figure 1 shows an expanded view of the data in the form of a two-dimension display in the region of tetrachlorodibenzo-p-dioxins (tetraCDDs) and tetrachlorodibenzofurans (tetraCDFs), measured using the picosecond laser. All native 12 C-congeners of tetraCDD/Fs, in addition to the 13 C-congeners that had been added to the sample solution as internal standards, could be clearly observed, and the intensity distributions of the isotope peaks were identical to those calculated from the natural abundance of the chlorine atom. Thus, tetraCDD/Fs as well as other CDD/Fs congeners can easily be identified using two-dimensional display data.…”

“…[11][12][13][14][15][16][17][18][19][20][21] The MPI technique reduces undesirable interfering signals and enables the acquisition of a mass spectrum with fewer fragment peaks.…”

Rapid Analysis of Gasoline-Contaminated Soil Using Multiphoton Ionization/Time-of-Flight Mass Spectrometry

“…[13][14][15][16] MPI/TOFMS combines a high selectivity for aromatic compounds with a high tolerance to contamination. 17,18 In environmental analysis, both content and concentration in real samples are, of course, unknown before measurement. Therefore, it is difficult to decide whether GC could be applied to a real sample.…”

Determination of persistent organic pollutants by gas chromatography/laser multiphoton ionization/time-of-flight mass spectrometry

“…Ultraviolet (UV) multiphoton ionization (MPI) is a useful technique for the efficient ionization of aromatic hydrocarbons, since they have a strong absorption band as the result of the π-π* transition in the UV region. This favorable issue also provides an improved selectivity, resulting in a reduction in the number of undesirable signals arising from the interfering compounds that are present in the sample [8,9]. In addition, a pulsed laser ionization technique would also be suitable for being combined with time-of-flight mass spectrometry, which would allow the immediate and efficient measurement of a mass spectrum with little or no degradation in sensitivity.…”