Quantification of 21 metabolites of methylnaphthalenes and polycyclic aromatic hydrocarbons in human urine

Abstract

Polycyclic aromatic hydrocarbons (PAHs) and their alkylated derivatives, such as methylnaphthalenes (MeNs), are harmful pollutants ubiquitously present in the environment. Exposure to PAHs has been linked to a variety of adverse health effects and outcomes, including cancer. Alkyl PAHs have been proposed as petrogenic source indicators because of their relatively high abundance in unburned petroleum products. We report a method to quantify 11 urinary methyl naphthols (Me-OHNs), metabolites of 1- and 2-methylnaphthalenes, and 10 monohydroxy PAH metabolites (OH-PAHs), using automated liquid-liquid extraction and isotope dilution gas chromatography tandem mass spectrometry (GC-MS/MS). After spiking urine (1 mL) with 13C-labeled internal standards, the conjugated target analytes were hydrolyzed enzymatically in the presence of ascorbic acid. Then, their free species were preconcentrated into 20% toluene in pentane, derivatized and quantified by GC-MS/MS. The 11 Me-OHNs eluted as 6 distinct chromatographic peaks, each representing 1–3 isomers. Method detection limits were 1.0–41 pg/mL and the coefficients of variance in quality control materials were 4.7–19%. The method was used to analyze two National Institute of Standards and Technology’s Standard Reference Materials and samples from 30 smokers and 30 non-smokers. Geometric mean concentrations were on average 37 (Me-OHNs) and 9.0 (OH-PAHs) fold higher in smokers than in non-smokers. These findings support the usefulness of Me-OHNs as potential biomarkers of non-occupational exposure to MeNs and sources containing MeNs.

Development of urine standard reference materials for metabolites of organic chemicals including polycyclic aromatic hydrocarbons, phthalates, phenols, parabens, and volatile organic compounds

“…With SRMs 3672 and 3673 being the first reference materials characterized for OH-PAHs, they will be useful in future studies to verify the methods used. In a study recently published by CDC, Li et al [27] used SRMs 3672 and 3673 to validate a new GC-MS/MS method for quantifying 21 metabolites of methylnapthalenes and PAHs in human urine. In the development of the method, they confirmed the certified values for the OH-PAHs [27].…”

Urinary concentrations of PAH and VOC metabolites in marijuana users

“…We measured urinary SCN using ion chromatography coupled with ESI-MS/MS with a LOD of 20 ng/mL (Blount and Valentin-Blasini, 2006; Valentín-Blasini et al, 2007). We measured urinary OH-PAHs using isotope-dilution gas chromatography (GC) coupled with MS or MS/MS with LODs in the range of 1.0–19 picograms per milliliter (pg/mL) (Li et al, 2006, 2014). We measured sCOT using HPLC coupled with atmospheric ionization (API)–MS/MS with a LOD of 0.015 ng/mL for all NHANES participants (Bernert et al, 2000).…”

Repeatedly high polycyclic aromatic hydrocarbon exposure and cockroach sensitization among inner-city children

“…While many epidemiological studies have demonstrated that long-term exposure to traffic-related air pollution (e.g., particulate matter less than 2.5 µm (PM 2.5 ) and polycyclic aromatic hydrocarbons (PAH)) were associated with the increased risk of developing asthma and asthma-related symptoms in children (Gehring et al 2010; Jung et al 2012; McConnell et al 2010), it is less clear whether traffic-related air pollutants contribute to the development of allergic sensitization given inconsistent results. For example, while few studies reported positive associations between long-term exposure to outdoor traffic-related air pollution (e.g., PM 2.5 , PM 2.5 absorbance and NO x ) and allergic sensitization to outdoor allergens (i.e., pollen) (Morgenstern et al 2008; Nordling et al 2008), a meta-analysis on five European Birth prospective cohort studies (i.e., BAMSE-Sweden, LISAplus and GINIplus-Germany, MASS-Great Britain, and PIAMA-The Netherlands) indicated that the long-term exposure to those air pollutants was not associated with the development of allergic sensitization in children (Gruzieva et al 2013).…”