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

Multiphoton ionization/time-of-flight mass spectrometry (MPI/TOFMS) was modified for the rapid analysis of gasoline-contaminated soil. This technique uses a nanosecond laser emitting at 266 nm, and has the potential to produce the mass spectrum for gasoline 30 min after sampling. The rapidity and robustness of the method can be applied to the screening of gasoline-contaminated soils while minimizing the risk of contamination when gas chromatograph (GC) is used. GC/MPI/TOFMS was used for a simultaneous determination of aromatic compounds of gasoline in a soil sample, and this was achieved without interference. A peak for toluene can be observed from 0.02 ng of gasoline, and ten peaks of aromatic hydrocarbons, which are sensitive to measurement by a laser, can be observed from 0.65 ng of gasoline. The MPI/TOFMS had good sensitivity and selectivity, and was therefore useful for the rapid analysis of gasoline-contaminated soils.