Gasoline, Kerosene, and Diesel Fingerprinting via Polar Markers

Venturi easy ambient sonic-spray ionization mass spectrometry working in the liquid mode (VL-EASI-MS) is shown to provide rapid and reliable characterization of crude oil distillates. With no extraction or pretreatments, samples of gasoline, kerosene, diesel, and admixtures of gasoline/diesel and gasoline/kerosene were directly analyzed by VL-EASI(+)-MS. Homologous series of natural N-heteroaromatics were detected in their protonated forms providing typical profiles of polar markers. For gasoline, VL-EASI(+)-MS detects a homologous series of mainly C1–C5 alkyl pyridines. For kerosene, a typical series of alkylated tetrahydroquinolines is detected. For diesel, the V-EASI(+)-MS profile is much richer because of the detection of several classes of many N-heteroaromatics. VL-EASI(+)-MS is also shown to provide typical spectra for petrochemical gasolines detecting specific antioxidants. Admixtures of gasoline/kerosene and gasoline/diesel are also clearly characterized with limits of detection of 10 and 1% (v/v), respectively. Fourier transform-ion cyclotron resonance mass spectrometry (FT-ICR MS) has been used to confirm assignments of the polar markers detected by VL-EASI(+)-MS.