Journal of Chromatography B, 879 (2011) 3592–3598 Contents lists available at SciVerse ScienceDirect Journal of Chromatography B jo u r n al hom epage: www.elsevier.com/locate/chromb Method development for the measurement of quinone levels in urine Dianne Lim a , Akihiro Ikeda a , Kennedy K.-T. Vu a , Kent T. Yamaguchi b , Tim R. Tyner b , Alam S. Hasson a,∗ a Department of Chemistry, California State University, Fresno, 2555 East San Ramon Avenue M/S SB70, Fresno, CA 93740, USA b Department of Surgery, University of California San Francisco Fresno Medical Education Program, USA a r t i c l e i n f o Article history: Received 14 June 2011 Accepted 28 September 2011 Available online 6 October 2011 Keywords: Quinones Polyaromatic hydrocarbons Urine analysis a b s t r a c t A method was developed for the quantification of 1–4 ring quinones in urine samples using liquid–liquid extraction followed by analysis with gas chromatography–mass spectrometry. Detection limits for the ten quinones analyzed are in the range 1–2 nmol dm -3 . The potential use of this approach to monitor urinary quinone levels was then evaluated in urine samples from both Sprague-Dawley rats and human subjects. Rats were exposed to 9,10-phenanthraquinone (PQ) by both injection and ingestion (mixed with solid food and dissolved in drinking water). Urinary levels of PQ were found to increase by up to a factor of ten compared to control samples, and the levels were found to depend on both the dose and duration of exposure. Samples were also collected and analyzed periodically from human subjects over the course of six months. Eight quinones were detected in the samples, with levels varying from below the detection limit up to 3 mol dm -3 . © 2011 Elsevier B.V. All rights reserved. 1. Introduction It is now widely accepted that exposure to high levels of air pol- lutants such as ozone and particulate matter may lead to adverse health effects. Much of the evidence for health impacts comes from epidemiological studies linking elevated concentrations of various pollutants to increases in mortality and morbidity, e.g. [1–7]. While the evidence for the health effects of air pollution is overwhelm- ing, the mechanisms via which exposure may lead to measurable, clinical symptoms are not well understood and are an active area of research. Particulate matter with a diameter smaller than 2.5 m (PM2.5) is one of the criteria pollutants regulated by the US federal gov- ernment. There is now a large body of literature documenting the impacts of particulate matter (PM) on human health. Air pollu- tion from various sources is an important contributor to morbidity and mortality [8–13], independent of exposure to other pollu- tants, severe weather or seasonal changes [14–17]. It is generally accepted that exposure to particulate matter may result in oxida- tive stress that may overwhelm the lung’s defense mechanisms, resulting in inflammation and, potentially, a measurable health effect, e.g. [18,19]. The origin of the oxidative stress is still the subject of debate. PM2.5 is a complex mixture of inorganic and organic constituents, and particles are known to contain a range of chemical components that may be involved in initiating oxidative stress. These include metals (such as iron and copper) [20–23] and ∗ Corresponding author. Tel.: +1 559 278 2420; fax: +1 559 278 4402. E-mail address: ahasson@csufresno.edu (A.S. Hasson). organics (such as polyaromatic hydrocarbons (PAHs) and quinones) [24–29]. To better understand the relationship between inhalation of PM components, oxidative stress and inflammation, it is necessary to accurately measure exposure to these chemical constituents. Various approaches have been taken to evaluate exposure to envi- ronmental pollutants. Predictive models have been developed to assess exposure based on estimated or measured atmospheric pol- lutant levels, proximity to the pollutant source, and daily behavior of the population [30–34]. When atmospheric levels of pollutants are not routinely monitored (as in the case of quinones), this approach typically requires a number of assumptions to be made that may limit the accuracy of the predicted exposure. This is likely to be amplified in studies with a small sample size, in part due to the potentially large impacts of differences in daily routine that should be averaged out over large sample populations. Personal monitors have also been used to measure exposure of subjects to PM2.5 and some of its chemical constituents. These typically consist of a particle size-selective inlet connected to a sampling pump that is worn by the subject. Personal monitors have been widely used to measure exposure to PM mass, e.g. [35–39], as well as exposure to specific chemical constituents [40–42]. While personal monitors provide an excellent measure of exposure, they are expensive to use with larger sample populations, and since they must be car- ried during the study period, they are somewhat intrusive for the subjects using them. An alternative approach to monitor exposure is to use environ- mental biomarkers. Exposure to pollutants may lead to their uptake into the body, where they are ultimately excreted (either directly or after they have been metabolized). Concentrations of the pollutant 1570-0232/$ – see front matter © 2011 Elsevier B.V. All rights reserved. doi:10.1016/j.jchromb.2011.09.051