Detection and quantitative analysis of polycyclic aromatic hydrocarbons by laser desorption/ionization mass spectrometry on monoisotopic silver-109 nanoparticles

This study demonstrates, for the first time, the quantitative detection of polycyclic aromatic hydrocarbons (PAHs) using monoisotopic silver-109 nanoparticle-enhanced targets in laser desorption/ionization mass spectrometry (109AgNPET LDI MS). Ten PAHs — anthracene, benzo(a)anthracene, benzo(a)pyrene, benzo(e)pyrene, chrysene, fluoranthene, perylene, phenanthrene, pyrene, and triphenylene — were analyzed, represented by four distinct molecular formulas, with radical cations (M+•) appearing as the predominant species in the MS spectra. The method yielded low chemical background, limited to silver cluster signals, enabling high-sensitivity analysis without matrix-related interferences. Limits of detection (LOD) ranged from 24 pg/mL for benzo(a)pyrene, benzo(e)pyrene, and perylene to 6.97 ng/mL for benzo(a)anthracene, chrysene, and triphenylene. Compared with existing methods, 109AgNPET LDI MS exhibited sensitivity surpassing or comparable to LC-MS, and in the case of benzo(a)pyrene, equaled the GC-MS, while eliminating sample pre-extraction or concentration steps. The results establish 109AgNPET LDI MS as a viable, rapid, and preparation-free approach for sensitive PAH analysis.