Determination of Methoxyphenols in Ambient Atmospheric Particulate Matter:  Tracers for Wood Combustion

Abstract

Combustion of wood and other biomass fuels produces source-specific organic compounds arising from pyrolysis of lignin, including substantial amounts of 4-substituted methoxylated phenolic compounds (methoxyphenols). These compounds have been used as atmospheric markers to determine the contribution of wood smoke to ambient atmospheric fine particulate matter (PM). However, reliable quantification of methoxyphenols represents an analytical challenge because these compounds are polar, semi-volatile, and somewhat reactive. We reportherein an improved gas chromatographic-mass spectrometric (GC/MS) method for the sensitive and reliable determination of methoxyphenols in low-volume ambient PM samples. Deuterated standard compounds are added to the environmental samples prior to extraction to determine analyte recoveries in each sample. Analytical figures of merit for the assay, as applied to ambient PM2.5 and PM10 samples are as follows: recovery = 63-100%; precision = 2-6%; analytical limit of detection (S/N 2) = 0.002 microg/mL; limit of quantitation = 0.07-0.45 ng/m3 (assuming a 14 m3 sample). The improved method was applied to ambient PM samples collected between 1999 and 2000 in Seattle, WA. Particle-bound methoxyphenol concentrations in the range <0.1 to 22 ng/m3 were observed and the methoxyphenols were present almost exclusively in the fine (PM2.5) size fraction. We also demonstrated that XRF analysis of samples of atmospheric PM collected on Teflon filters significantly reduced the levels of methoxyphenols measured in the PM samples in subsequent assay of the same filters. Therefore, XRF analysis of filters, commonly undertaken to obtain trace element concentrations for use in source apportionment analyses, would preclude the subsequent analysis of those filters for methoxyphenols and other similarly semivolatile or reactive organic chemicals.

Biological monitoring of smoke exposure among wildland firefighters: A pilot study comparing urinary methoxyphenols with personal exposures to carbon monoxide, particular matter, and levoglucosan

“…Filters were extracted by sonication in ethylacetate, extracts were reduced in volume under N 2 , derivatized with MSTFA/pyridine, and analyzed for LG by using GC/MS as described previously (Simpson et al, 2004(Simpson et al, , 2005. Samples were amended with LG prior to extraction to monitor analyte recovery, and unexposed filters were extracted with each batch of environmental samples as assay blanks.…”

Experimental and theoretical studies on gas-phase reactions of NO3 radicals with three methoxyphenols: Guaiacol, creosol, and syringol

“…Most of the methoxyphenols produced from the pyrolysis of lignin are guaiacol and syringol derivatives (Hawthorne et al, 1989;Hays et al, 2002;Re-Poppi and Santiago-Silva, 2002;Simpson et al, 2005;Mazzoleni et al, 2007). Since methoxyphenols are unique to biomass combustion (Hawthorne et al, 1988(Hawthorne et al, , 1989Standley and Simoneit, 1990;Simoneit et al, 1993), they have been considered as possible atmospheric wood smoke pollution tracers (Hawthorne et al, 1988(Hawthorne et al, , 1989Simoneit et al, 1993).…”

Levoglucosan and phenols in Antarctic marine, coastal and plateau aerosols

“…Methoxy phenols degrade in the atmosphere, where 2-methoxyphenol (guaiacol) and its isomers in the gas-phase react with OH hydroxyradicals (Coeur-Tourneur et al, 2010), while phenols react with 3 C ⁎ (aromatic carbonyl) and some methoxy phenols in particulate matter react with O 3 (Net et al, 2011), NO 3 (Liu et al, 2012), 3 C ⁎ , OH (Li et al, 2014;Yu et al, 2014), and UV (Li et al, 2014). Most previous determinations of PCs in aerosols were performed in zones close to residential areas using biomass burning in domestic heating (Bari et al, 2010(Bari et al, , 2011Dutton et al, 2009Dutton et al, , 2010He et al, 2010;Simpson et al, 2005;Ward et al, 2011) or else in zones heavily impacted from wildfire smoke (Ward et al, 2006). PCs occur in high concentrations near these biomass burning sources, ranging from 10 s to greater than 10,000 pg m − 3 (Bari et al, 2010(Bari et al, , 2011Dutton et al, 2009Dutton et al, , 2010He et al, 2010;Simpson et al, 2005;Ward et al, 2011).…”

“…Most previous determinations of PCs in aerosols were performed in zones close to residential areas using biomass burning in domestic heating (Bari et al, 2010(Bari et al, , 2011Dutton et al, 2009Dutton et al, , 2010He et al, 2010;Simpson et al, 2005;Ward et al, 2011) or else in zones heavily impacted from wildfire smoke (Ward et al, 2006). PCs occur in high concentrations near these biomass burning sources, ranging from 10 s to greater than 10,000 pg m − 3 (Bari et al, 2010(Bari et al, , 2011Dutton et al, 2009Dutton et al, , 2010He et al, 2010;Simpson et al, 2005;Ward et al, 2011). In the Arctic, PCs have considerably lower concentrations with mean values (for particle sizes of 10 μm to b0.49 μm) of 14 pg m −3 (Zangrando et al, 2013).…”