Influence of smear matrix types on detection behaviors and efficiencies of polycyclic aromatic hydrocarbons using ion mobility spectrometry.

Influence of smear matrix types on detection behaviors and efficiencies of polycyclic aromatic hydrocarbons (PAHs) with different molecular weights in ion mobility spectrometry (IMS) were investigated. Various smear matrices of stainless steel mesh (SM), cellulose paper (CP), and cotton fabric (CF) were employed. Anisole was used as the solvent and IMS analysis was performed without evaporation step of the solvent to apply charge transfer reactions between PAH molecules and the molecular ions of solvent. Shapes of reactant ion peaks (RIPs) were varied according to the smear matrix types. At the beginning of the sample inlet, intensity of RIPs of air and moisture notably decreased due to the lots of solvent vapor. The SM with good gas permeability showed relatively strong RIPs of air and moisture, whereas the CP with no gas permeability showed weak ones. Detection times and efficiencies of PAH ions were varied according to the smear matrix types as well as the kinds of PAHs. PAHs were on the whole detected well in 1-3 s after the sample inlet. Detection limits of PAHs measured using the SM were slightly better than those measured using the CP, while those measured using the CP were much better than those measured using the CF. The experimental results could be explained by structures of the smear matrices and evaporation behaviors of the PAH solutions.