Analysis of carcinogenic polycyclic aromatic hydrocarbons in complex environmental mixtures by LC-APPI-MS/MS

Here we developed a highly sensitive, fast and reliable liquid chromatography tandem mass spectrometry (LC-MS/MS) method for the detection and analysis of 16 different polycyclic aromatic hydrocarbons (PAHs) and nitro-PAHs that have been identified as carcinogens and classified according to their biological potency. Comparison to standard analysis procedures based on gas chromatography–mass spectrometry (GC–MS) instrumentation demonstrated an improved easiness of sample preparation and sensitivity of detection achieved with the new LC-MS/MS method employing an atmospheric pressure photoionization (APPI) source attached to an API 4000 mass spectrometer (LC-APPI-MS/MS). The favorable outcome could be confirmed by analyzing complex mixtures such as certain Standard Reference Materials (SRMs) obtained from the National Institute of Standards & Technology (NIST), i.e., SRM 1975 and SRM 2975, and several diesel exhaust soots provided by the German automobile industry. Certified concentrations of individual analytes provided by NIST not only could be confirmed, but additional extremely potent carcinogens such as several isomeric hexacyclic dibenzopyrenes (DBPs), 5-methylchrysene (5-MC), and others have been detected in these crude samples in a concentration range down to below 1 ng g−1 raw material.

Graphical abstract.Figure optionsDownload full-size imageDownload as PowerPoint slideHighlights► Here we developed an improved LC-APPI-MS/MS method for analysis of high molecular-weight and carcinogenic PAHs and nitro-PAHs. ► Validation of the method was performed through analysis of certified Standard Reference Materials. ► Regulatory needs usually prompt laboratories to perform PAH analysis based on LC-UV/FLD or GC–MS methodology. ► Due to its easiness, specificity and reduced sample preparation time, the new LC-APPI-MS/MS approach is now being suggested as reference method for PAH analysis in complex mixtures.