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

Abstract

An authentic mixture of polychlorinated biphenyls was measured using a short wide-bore capillary column for the group separation of major components present in an actual sample of Kanechlor. The limits of detection were improved by ca. 2 fold in comparison with those obtained using a conventional capillary column, since the retention time was reduced and the amount of analytes introduced into the mass spectrometer per unit time could be increased. On the other hand, surface-water and sediment samples containing polycyclic aromatic hydrocarbons (PAHs) were collected from the river located in the vicinity of a waste water treatment plant. Even acenaphthylene, a minor component of the mixture could be measured for the sediment sample, and the concentrations were determined for several heavy PAHs. As demonstrated, a technique involving laser multiphoton ionization/time-of-flight mass spectrometry was useful as a sensitive and selective analytical tool for the trace analysis of persistent organic pollutants in an environmental sample.

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

“…29 Water (1 L) was collected from a river in China, and solid particles were removed by passing the sample solution through a filter. An aliquot of an artificial standard solution (100 μL) containing 4 ppm of each PAH was added to pure water for determining the recovery of the analytes in the pretreatment process.…”

“…This can be explained by the fact that the excited-state lifetimes for the PAHs are longer than the pulse width of the picosecond laser, since no heavy atoms are present in the molecule. 18,29 It should be noted that the LODs for the picosecond laser were considerably less than 1 fg for NAP, PHE, PYR, BaA, CHR, BaP. When the sample solution containing PAHs was further diluted and measured at a concentration of 4.5 fg μL -1 , the LODs were decreased to 0.9 and 0.5 fg for FLT and FLU, respectively (LODs were <1 fg for the above 6 PAHs).…”

Multiphoton ionization mass spectrometry of nitrated polycyclic aromatic hydrocarbons

“…A laser emitting at 267 nm, i.e., the third harmonic emission of a Ti:sapphire laser, has been successfully employed for the detection of PAHs [17,37]. On the other hand, NPAHs have absorption bands at around 230-260 nm, 275-300 nm, and 350-405 nm [30,[34][35][36].…”

Analysis of Parent/Nitrated Polycyclic Aromatic Hydrocarbons in Particulate Matter 2.5 Based on Femtosecond Ionization Mass Spectrometry

“…In fact, PPAHs specified by the Environmental Protection Agency of the United States (US-EPA), dioxins/dibenzofurans/biphenyls, explosives, pesticides, and polybrominated diphenyl ether, have been measured to date [9]. It should be noted that PPAHs in a surface water sample in China was measured using GC/MPI/ TOF-MS [10]. Three different laser-based techniques for online analysis of particles (i.e., one-step laser desorption/ionization, two-step laser desorption/photoionization, and thermal desorption/photoionization) were used for the measurement of aerosol samples such as a wood ash and exhaust fumes of a gasoline-driven car [11].…”