Detection of nitrated and oxygenated polycyclic aromatic hydrocarbons using atmospheric pressure chemical ionization high resolution mass spectrometry

Abstract

Polycyclic aromatic hydrocarbons (PAHs) are common pollutants in the atmosphere and have long been recognized to be toxic to humans. These PAHs can be oxidized into more toxic products in both the gas and condensed (on the surface of suspended particulate matter) phases. In this work, we report fragmentation patterns observed atmospheric pressure chemical ionization with high resolution mass spectrometry (APCI-HRMS) for PAH oxidation products. A representative group of 18 PAH derivatives containing carbonyl (oxo-PAHs), hydroxyl (hydroxy-PAHs), carboxyl (carboxy-PAHs), and/or nitro (nitro-PAHs) groups was studied. Ionization of carboxy-RAHs in negative mode yielded common fragments of [M-H]-, [M-H-CO]-, and [M-H-CO 2 ]-. Oxo-PAHs provided common fragments of [M+H] + , [M+H-CO] + and [M+H-2CO] + in positive mode and [M+e-]in negative mode. Mass spectra of aldehydes exhibited common fragments of [M+H] + , [M+H-CO] + , and [M+H-O] + in positive mode and [M+e-]and [M-H+O]in negative mode. For all nitro-PAHs, [M+H] + , [M+H-O] + and [M+3H-O 2 ] + ions were observed in positive mode. On the basis of the APCI-HRMS analysis of standards, eight reaction products of pyrene oxidation under heterogeneous conditions were characterized. HRMS data, specific fragments and common ions such as that of 205 m/z, characteristic for carbonyl phenanthrene, enabled the identification of the oxidation products.

Analytical progress and challenges for the detection of oxygenated polycyclic aromatic hydrocarbon transformation products in aqueous and soil environmental matrices: A review

“…ESI has been used in the quantification of more polar components including COOHPAH in contaminated groundwater (Ohlenbusch et al, 2002), OHPAH in wastewater (Pojana and Marcomini, 2007), and OHPAH and conjugated metabolites in supernatants of fungal PAH degradation incubations as well as urine (Schmidt et al, 2010a;. At the same time, the use of APCI is growing for these more polar compounds and is generally preferred for OPAH analysis, particularly in atmospheric samples where the technique has been more widely adopted (Boll et al, 2015;Cochran et al, 2016;Kishikawa and Kuroda, 2014;Nyiri et al, 2016;O'Connell et al, 2013;Walgraeve et al, 2010). APPI may be preferred for the analysis of parent PAH (Hollosi and Wenzl, 2011) and has been used more recently for analysis of OHPAH in soils (Avagyan et al, 2015) Matrix effects can be substantial for all LC-MS applications, in particular as other constituents including salts, buffers, or the solvent itself can cause residue build-up in instruments, compete with analytes, change charge-transfer characteristics, or lead to additional interactions such as ionpairing.…”

Reactive indoor air chemistry and health—A workshop summary

“…Gas-phase oxidation products have been measured using Fourier transform infrared spectroscopy (FTIR), gas and high-performance liquid chromatography/mass spectrometry (GC/MS and HPLC/MS), but recent techniques such as PTR-MS and atmospheric-pressure ionization mass spectrometry (API-MS) provide the advantage of real-time or near real-time data of target compounds coupled with high sensitivity (Cochran et al, 2016; Nozière et al, 2015).…”

The influence of different types of reactant ions on the ionization behavior of polycyclic aromatic hydrocarbons in corona discharge ion mobility spectrometry

“…Young et al analyzed PAHs on borosilicate glass using laser desorption/ionization and IMS, 45 whereas Eiceman and Vandiver used photoionization‐IMS, 46 and other workers used IMS‐MS 47,48 . The analysis of PAHs using corona discharge MS has been reported, 24,26,49 but there have been no reports of their analysis using IMS coupled with corona discharge ionization except for our previous work 35 . In the present work, the influence of the types of RIs on the ionization behavior of PAHs was investigated by introducing the sample solution spotted on a smear matrix into the sample inlet region before evaporation of the solvent.…”