Ultrasensitive Determination of Polycyclic Aromatic Compounds with Atmospheric-Pressure Laser Ionization as an Interface for GC/MS

• Published in: Analytical chemistry (Washington) 2007-06, Vol.79 (11), p.4135-4140
• Main Authors: Schiewek, R, Schellenträger, M, Mönnikes, R, Lorenz, M, Giese, R, Brockmann, K. J, Gäb, S, Benter, Th, Schmitz, O. J
• Format: Article
• Language: English
• Subjects: Analytical chemistry; Atmospheric pressure; Chemistry; Chromatographic methods and physical methods associated with chromatography; Exact sciences and technology; Gas chromatographic methods; Mass spectrometry; Methods; Polycyclic aromatic hydrocarbons; Spectrometric and optical methods; Urine
• ISSN: 0003-2700; 1520-6882
• DOI: 10.1021/ac0700631

Recently we introduced atmospheric pressure laser ionization (APLI) as a complementary ionization method for coupling LC−MS systems (HPLC and CEC), allowing ionization of nonpolar aromatic compounds via near-resonant two-photon excitation. In this paper, we demonstrate that APLI with the same source enclosure as for LC coupling is also suited for hyphenation of GC with atmospheric-pressure ionization mass spectrometry. This technique permits the qualitative and quantitative determination of aromatic compounds in an ultralow concentration range, as we show here with polycyclic aromatic hydrocarbons (PAHs), alkylated PAHs, and hetero-PAHs as examples. The outstanding sensitivity is demonstrated for chrysene, with a detection limit of 22 amol. Polar functional groups reduce the sensitivity, but after methylation or silylation, the analytes can also be determined very sensitively in complex matrixes, as is shown with 1-hydroxypyrene in urine.