Phenol groups in Northeastern U.S. Submicron. Aerosol Particles Produced from Seawater Sources

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1 Phenol groups in Northeastern U.S. Submicron Aerosol Particles Produced from Seawater Sources Ranjit Bahadur, Timothy Uplinger, Lynn M. Russell,, Barkley C. Sive, Steven S. Cliff, Dylan B. Millet, Allen Goldstein, and Timothy S. Bates Scripps Institution of Oceanography, University of California San Diego, La Jolla CA , Institute for the Study of Earth, Ocean, and Space, University of New Hampshire, Durham NH 03824, Department of Applied Science, University of California Davis, Davis CA 95616, Department of Soil, Water, and Climate, University of Minnesota, St. Paul MN 55108, Department of Environmental Science, Policy, and Management, University of California Berkeley, CA 94720, and Pacific Marine Environmental Laboratory, National Oceanic and Atmospheric Administration, Seattle WA Sample Collection This section provides a brief overview of the instrument and sampling details for the atmospheric measurements used in this work. Further details and raw data for download are also available in the public domain via the ICARTT 2004 project data management system located at To whom correspondence should be addressed Scripps Institution of Oceanography University of New Hampshire University of California Davis University of Minnesota University of California Berkeley Pacific Marine Environmental Laboratory 1

2 (a) Appledore Island (AI). The sampling site was located at 42.6N and 70.2W, approximately 0.1 km from the coastline. FTIR : Submicron aerosol samples were collected on 37 mm Teflon filters downstream of a 1 µm impactor (SCC 2.229PM1, BGI Inc.,Waltham, Massachusetts) used for particle sizing. Air was drawn at a rate of 8.3 LPM though the inlet located at a height of 40 m, and aerosols were sampled at ambient temperature and RH. No rain shield was employed over the inlet.(1). IC : Size-segregated aerosols were sampled using Graseby-Anderson 235 cascade impactors, with a Liu-Pui type inlet, and polycarbonate impaction substrates and quartz-fiber backup filters (Palliflex 2500 QAT-UP). The average sampling rates for impactor and bulk aerosol sampling were 1.0 and 1.2 m 3 min 1 respectively. All air volumes reported herein were adjusted to standard temperature (0 C) and pressure (1 atm). Aerosol sampling was suspended during infrequent precipitation and heavy fog events(2). GCMS : A single Shimadzu GC-17A gas chromatograph housed four separation columns as follows: one 50 m x 0.53 mm i.d., 10-µm film thickness CP-A12O3/Na2SO4 PLOT column, one 60 m x 0.25 mm i.d., 1-µm film thickness OV-1701 column (Ohio Valley Specialty Chemical, Marietta, OH), one 60 m x 0.32 mm i.d., 1.0-µm film thickness VF-5ms column (Varian Inc.), and one 60 m x 0.25 mm i.d., 1.4-µm film thickness OV-624 column (Ohio Valley Specialty Chemical). For the GC/MS, electron impact mode was used for sample ionization along with single ion monitoring(3 5). (b) Chebogue Point (CP). The sampling site was located at 47.3N and 66.1W, approximately 0.1 km from the coastline. FTIR : The inlet was located at a height of 10 m and aerosols were sampled at ambient temperature and RH, with no rain shield. Air was sampled at a rate of 6.0 LPM and aerosol particles sized at 1 µm using a cyclone impactor (SCC 2.229PM1, BGI Inc.,Waltham, Massachusetts) (1). GCMS [TAG] : Air was sampled through 3/8 inch teflon tubing with the particle size cut made using a PM2.5 cyclone (SCC, BGI Inc., Waltham, MA) at a typical flow rate of 8 LPM. Samples were thermally desorbed after collection and separated by gas chromatography (GC, Agilent 6890) 2

3 using a Rtx-5MS column (30 m, 0.25 mm i.d., 0.25 µm film thickness; Restek Corp.) while ramping the GC oven from 48 C to 300 C at a rate of 8.6 C min 1. Compound identification and quantification was achieved using electron impact ionization and quadrupole mass spectrometry (EI + QMS, Agilent 5973), with simultaneous flame ionization detection (FID) used for further quantification(6, 7). GCMS [VOCs] : The system was configured for analysis of C3ŰC6 alkanes, alkenes, and alkynes on the FID channel, and a range of other VOCs, including aromatic, oxygenated, alkyl nitrate, and halogenated compounds on the MSD channel. Carbon dioxide and ozone were scrubbed from the FID channel subsample (Ascarite II), and ozone was removed from the MSD channel subsample (KI impregnated glass wool). Preconcentration was accomplished using a combination of thermoelectric cooling (-15 C) and adsorbent trapping. Samples were injected into the GC by rapidly heating the trap assemblies to 200 C(6). XRF : Samples were collected using the UC Davis 8-stage DRUM impactor and analyzed by synchrotron x-ray fluorescence for elements. Sampler operated at 55% relative humidity by heating inlet and collected samples in 3-hour increments(8). PTR-MS : Samples were taken at 10 m through Teflon tubing (PFA, ID 4 mm, 15 m length) kept several degrees above ambient air temperature (i.e., C) with a self-regulating heating cable (SLR3, Omega, 3 W/ft, Tmax 65 C) at a rate of 500 cc/min. Precipitation and coarse particles by were excluded from the sampling line using a funnel (PFA) and a filter (PTFE, 2 µm pore size). A solenoid valve (PTFE) provided the option to direct the sample air through a catalytic converter (Platinum coated quartz wool heated to 350 C) allowing the quantification of both the instrumental background and contamination of the inlet system(9). (c) R/V Ronald Brown (RB). During the ICARTT 2004 experiment, the ship traveled the area between 41.5N and 44.5N, and 66W and 71 W. Sample air for all aerosol measurements was drawn through a 6-m mast located 18 m above sea level and forward of the ship s stack. Air was sampled over the ship s bow and sector control was employed to limit contamination from the ship s exhaust(10). 3

4 FTIR : Samples were collected at 6.0 LPM through the common inlet, heated to maintain sample air at 55% RH. PILS : A Berner-type impactor with a 50% aerodynamic cutoff diameter of 1.1 um was upstream of the PILS which ran at 15 LPM with the flow controlled by a critical orifice, and a make up flow through a bypass line was added to maintain a flow of 30 LPM through the impactor. Two denuders were located in series downstream of the impactor. These were 1) a URG denuder coated with sodium carbonate for the removal of gas phase acids, and 2) a URG denuder coated with citric acid to remove gas phase bases. Cation analysis was carried out using a Metrohm Peak C2-100 column and anion analysis was carried out using a Methrohm Peak ASupp5-100 with a packed bed suppressor. PILS concentrations were corrected by comparison of NH + 4 to the submicron stages of a 2 and 7 stage impactor(10). and SO2 4 concentrations GCMS : Ambient air was sampled at 15 LPM with a back pressure of 1.5 atmospheres. A portion of the airflow (200 cm 3 min 1 ) was injected into two independent Shimadzu GC-17A gas chromatographs. The first GC contained a 60 m x 0.25 mm I.D., 1.4 µm film thickness OV- 624 capillary column coupled to an ECD, used to separate and quantify various halocarbons and alkyl nitrates. The second GC contained a 50 m x 0.53 mm I.D., 10 µm film thickness CP- A12O3/Na2SO4 PLOT column coupled to an FID for the separation and quantification of the C 2 ŰC 6 NMHCs(4). Calibration of 3500 cm 1 peak During ICARTT 2004, an absorption peak at 3500 cm 1 above the broad hydroxyl background was observed, and identified as absorption by phenol groups. 3,4-dihydroxy benzoate and n-propyl 3,4,5-trihydroxy benzoate were chosen as representative compounds based on their reference library FTIR-absorption spectra. Calibration standards for the selected compounds were prepared from 1 mmol L 1 solutions in acetone that were atomized using a TSI model 3076 constant output recirculation atomizer. The polydisperse atomized samples were diluted by the addition of dry 4

5 air at a mixing ratio of 1:1, and a flow rate of 1.5 SLPM was used to collect particles on 37 mm teflon filters. Multiple samples were prepared by collecting aerosols for time periods between 20 and 60 min at 10 min intervals. The filters were stored in petri dishes under constant temperature and relative humidity for 24 hours prior to FTIR analysis to facilitate solvent evaporation. The net sample loading on each filter was determined gravimetrically using the difference in filter weights measured before and after loading. The filters were scanned using a Bruker Tensor 27 FTIR Spectrometer with a DTGS detector operating in the transmission mode. Each individual sample spectrum was determined by averaging 128 scans between 400 and 4000 cm 1 with a resolution of 4 cm 1 and subtraction of corresponding pre-sampling filter scans(1). Mass concentrations of functional groups were calculated using an automated algorithm that determines baselines and performs Gaussian peak fits to the spectra(11, 12). Phenol group concentrations during ICARTT 2004 A summary of the total number of samples collected, the number of samples with phenol group concentrations above detection limits of the broad hydroxyl IR absorption, upper and lower bounds of phenol group concentrations, and project averages for OM and PMF factors is presented in Figure S1. PMF Analysis Singular value decomposition was used to determine the optimum number of factors, and the robustness of the factor solution was examined by varying the rotation parameter FPEAK. Nonnegativity constraints were imposed on the solution spectra and the infrared spectra of field blanks were used to estimate the uncertainty in measured absorbance. Solutions utilizing between 3 and 6 factors reproduced measured organic mass within 10%. Varying the rotation parameter produced a highly robust solution with negligible differences in the residual (Q) matrix therefore a value of FPEAK=-0.4 was selected to minimize correlations between individual factors in each solution. 5

6 The absorption spectra of the PMF based source factors (ocean-derived, combustion, and biogenic) identified at three platforms during ICARTT 2004 are illustrated in Figure S2. The oceanderived factor spectra (Figure S2(a)) are dissimilar between the ground sites and the R/V Ronald Brown. All three platforms show a broad absorption in the organic hydroxyl region with negligible ammonium, but the spectra for the ground sites have large absorption peaks at 3500 cm 1, consistent with the larger fraction of samples with detectable phenol group concentrations at these sites. Combustion factor spectra (Figure S2(b)) show a large ammonium absorption at 3200 cm 1 for all three platforms, consistent with spectra observed in other urban environments(11). Biogenic factor spectra (Figure S2(c)) show a much smaller ammonium absorption than the combustion factor. The broad peak between 3000 and 3500 cm 1 (resulting in a smaller alkane group fraction) is coupled with a high non-acid carbonyl group absorption (approximately 3-4 times the magnitude in the other factors). The time-series contribution of the three PMF factors to samples collected during ICARTT 2004 is illustrated in Figure S3. The combustion derived factor shows episodes of high concentration at the ground sites between July 10-July 17, and July 27-July 30 on board the R/V Ronald Brown, corresponding to measured episodes of elevated continental urban outflow(1, 6). The time series at the ground sites do not contain any singular events dominated by the biogenic factor; but show a diurnal pattern with alternating high and low concentrations in 12 hr samples consistent with photochemical aerosol formation(13). The R/V Ronald Brown samples show a large contribution from the biogenic factor on July 27 and 28, consistent with observed high isoprene oxidation events(10). Correlations with tracers Sources associated with the three PMF factor were identified using correlations with co-measured VOCs from PTR-MS and GCMS measurements(2 7, 9, 10, 13 16), X-Ray Fluorescence (XRF) metals (CP)(8), and ions from PILS and impactor measurements (submicron fraction only) (RB)(10) 6

7 at each platform. High time resolution measurements (typically tracers) were averaged over the the sampling period corresponding to each FTIR sample. Only measurements with both start and stop times within the FTIR filter sampling time were included, this resulted in the discarding of a small number (<5%) of measurements that may have overlapped start/stop times. Measurements below the detection limit were set to 0, and any missing data were not included in the calculated averages. Correlations were determined using Standardized Major Axis (SMA) regression, which allows for error in both variables of a paired data set, and is more appropriate for a set of atmospheric measurements. Since the interpretation of the absolute values of Pearson s correlation coefficient R are difficult for a set of data with large noise, values of R were segregated into four subjective categories : no correlation (R<0.25), weak correlation (0.25<R<0.50), moderate correlation (0.50<R<0.75), and strong correlation (R>0.75). We do not make any conclusions on the lack of correlations with tracers, only the existence of correlations is considered while associating the factors with sources. The entire set of correlations between factors and tracers are summarized in Figures S4 (AI), S5 (CP), and S6 (RB), however tracers with less than 5 points that overlap filter times are excluded entirely. PSCF Analysis Three day back trajectories ending at the sampling platforms were computed using the Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) model(17) with hourly resolution at 50, 100 and 500 m above sea level and treated as a single ensemble to minimize the effect of selecting altitude. Periods in which the fractional contribution for each source factor was in the top 75th percentile were classified as high with the remainder classified as low, and the associated backtrajectories were grouped accordingly. The trajectories were interpolated into 15 min intervals and superposed on a domain centered around the sampling platform and gridded into a total of 250,000 cells (with dimensions approximately 45 km x 55 km). The probability for the source location was then determined as the normalized total count of high period trajectories for each grid cell. Grid 7

8 cells ranked in the lower 30% based on total trajectories traversed were excluded, since these can be unduly biased by a small number of trajectories. The threshold corresponded to approximately 500 trajectories for this data set. The phenol group containing source factor at the three ICARTT platforms is identified with an ocean-derived source based on correlations with tracers summarized in Figure 4 (main manuscript). The PSCF analysis based on air mass back trajectory analysis is illustrated in Figure S7, and indicates that the most probable source regions for this factor are located in North American coastal waters and dispersed areas of the Atlantic Ocean, consistent with the inferred ocean source. The corresponding back trajectories and probability density plots are illustrated in Figure S8. The PSCF results are consistent with earlier work on air-mass classification during ICARTT(4? ). PSCF has poor resolution in the grid cells immediately surrounding the measuring site due to insufficient variability between air mass trajectories. Repeating the analysis using 24 hr and 36 hr back-trajectories did not improve the resolution between local (Gulf of Maine) and long-range (Atlantic) ocean sources for the ocean-derived factor suggesting that phenol sources are located closer upwind to the measuring sites with negligible contributions from long range transport. Since the ocean-derived factor has winds from the North East (AI), South-South West (CP), and East (RB); the most proximate common overlap of these upwind areas are the waters of the Gulf of Maine. References (1) Gilardoni, S.; Russell, L. M.; Sorooshian, A.; Flagan, R. C.; Seinfeld, J. H.; Bates, T. S.; Quinn, P. K.; Allan, J. D.; Williams, B.; Goldstein, A. H.; Onasch, T. B.; Worsnop, D. R. Regional variation of organic functional groups in aerosol particles on four U.S. east coast platforms during the International Consortium for Atmospheric Research on Transport and Transformation 2004 campaign. Journal of Geophysical Research 2007, 112, D10S27. (2) Fischer, E.; Pszenny, A. A. P.; Keene, W.; Maben, J.; Smith, A.; Stohl, A.; Talbot, R. Ni- 8

9 tric acid phase partitioning and cycling in the New England coastal atmosphere. Journal of Geophysical Research 2006, 111, D23S09. (3) Sive, B. C.; Zhou, Y.; Troop, D.; Wang, Y. L.; Little, W. C.; Wingenter, O. W.; Russo, R. S.; Varner, R. K.; Talbot, R. Development of a cryogen-free concentration system for measurements of volatile organic compounds. Analytical Chemistry 2005, 77, 6989Ű (4) Zhou, Y.; Varner, R. K.; Russo, R. S.; Wingenter, O. W.; Haase, K. B.; Talbot, R.; Sive, B. C. Coastal water source of short-lived halocarbons in New England. Journal of Geophysical Research 2005, 110, D (5) Sive, B. C.; Varner, R. K.; Mao, H.; Blake, D. R.; Wingenter, O. W.; Talbot, R. A Large Terrestrial Source of Methyl Iodide. Geophysical Research Letters 2007, 34, L (6) Millet, D. B.; Goldstein, A. H.; Holzinger, R.; Williams, B. J.; Allan, J. D.; Jimenez, J. L.; Worsnop, D. R.; M., R. J.; White, R. C., A. B. Hudman; Bertschi, I. T.; Stohl, A. Chemical characteristics of North American surface layer outflow: Insights from Chebogue Point, Nova Scotia. Journal of Geophysical Research 2006, 111, D23S53. (7) Williams, B. J.; Goldstein, A. H.; Millet, D. B.; Holzinger, R.; Kreisberg, N. M.; Hering, S. V.; White, A. B.; Worsnop, D. R.; Allan, J. D.; Jimenez, J. L. Chemical speciation of organic aerosol during the International Consortium for Atmospheric Research on Transport and Transformation 2004: Results from in situ measurements. Journal of Geophysical Research 2007, 112, D10S26. (8) Cliff, S. U.C. Davis 8-Stage Rotating DRUM Impactor Sampler Elemental Data, ftp://ftp.al.noaa.gov/ucd_elemental_data. (9) Holzinger, R.; Millet, D. B.; Williams, B.; Lee, A.; Kreisberg, N.; Hering, S. V.; Jimenez, J.; Allan, J. D.; Worsnop, D. R.; Goldstein, A. H. Emission, oxidation, and secondary organic aerosol formation of volatile organic compounds as observed at Chebogue Point, Nova Scotia. Journal of Geophysical Research 2007, 112, D10S24. 9

10 (10) Quinn, P. K.; Bates, T. S.; Coffman, D.; Onasch, T. B.; Worsnop, D.; Baynard, T.; de Gouw, J. A.; Goldan, P. D.; Kuster, W. C.; Williams, E.; Roberts, J. M.; Lerner, B.; Stohl, A.; Pettersson, A.; Lovejoy, E. R. Impacts of sources and aging on submicrometer aerosol properties in the marine boundary layer across the Gulf of Maine. Journal of Geophysical Research-Atmospheres 2006, 111, D23. (11) Russell, L. M.; Takahama, S.; Liu, S.; Hawkins, L. N.; Covert, D. S.; Quinn, P. K.; Bates, T. S. Oxygenated Fraction and Mass of Organic Aerosol from Direct Emission and Atmospheric Processing Measured on the R/V Ronald Brown during TEXAQS/GoMACCS Journal of Geophysical Research Atmospheres 2009, 114, D00F05. (12) Liu, S.; Takahama, S.; Russell, L. M.; Gilardoni, S.; Baumgardner, D. Oxygenated organic functional groups and their sources in single and submicron organic particles in MILAGRO 2006 campaign. Atmospheric Chemistry and Physics Discussions 2009, 9, (13) Russell, L. M.; Mensah, A. A.; Fishcher, E. V.; Sive, B. C. S.; Varner, R. K. V.; Keene, W. C.; Stutz, J.; Pszenny, A. A. P. P. Nanoparticle growth following photochemical α- and β-pinene oxidation at Appledore Island during International Consortium for Research on Transport and Transformation/Chemistry of Halogens at the Isles of Shoals Journal of Geophysical Research 2007, 112, D10S21. (14) Warneke, C. et al. Biomass burning and anthropogenic sources of CO over New England in the summer Journal of Geophysical Research - Atmospheres 2006, 111, D23S15. (15) de Gouw, J. A. et al. Sources of particulate matter in the northeastern United States in summer: 1. Direct emissions and secondary formation of organic matter in urban plumes. Journal of Geophysical Research 2008, 111, D (16) Zhou, Y.; Mao, H.; Russo, R. S.; Blake, D. R.; Wingenter, O. W.; Haase, K. B.; Ambrose,; Varner, R. K.; Talbot, R.; Sive, B. C. Bromoform and dibromomethane measurements in the 10

11 seacoast region of New Hampshire, Journal of Geophysical Research 2008, 113, D (17) HYSPLIT - Hybrid Single Particle Lagrangian Integrated Trajectory Model, 11

12 AI CP RB Total Samples Phenol gp. above DL Average project OM, µg m Avg. Phenol gp. (LB), µg m ± ± ±0.09 Avg. Phenol gp. (UB), µg m ± ± ±0.06 Ocean-derived factor, µg m Fossil fuel combustion factor, µg m Terrestrial biogenic factor, µg m Figure S1 : Summary of collected samples, measured OM, phenol group concentrations (lower bound calculated with samples below detection limit set to 0, and upper limit calculated from only samples above detection limit), and average concentrations of three persistent PMF factors during ICARTT

13 Absorbance Absorbance (a) (b) Absorbance Wavenumber (c) Figure S2 :Baselined FTIR absorption for the (a) ocean-derived factor, (b) combustion factor, and (c) biogenic factor. Spectra are shown in red for Appledore Island, green for Chebogue Point, and black for the R/V Ronald Brown. 13

14 OM(µg m 3 ) (a) OM(µg m 3 ) OM(µg m 3 ) (b) (c) Jun 28 Jul 07 Jul 17 Jul 27 Aug 6 Aug 16 Date Figure S3 : Time series for PMF factors at (a) Appledore Island, (b) Chebogue Point, and (c) R/V Ronald Brown during ICARTT The combustion factor is indicated in red, biogenic factor in yellow, and ocean-derived factor in blue. 14

15 Figure S4 : Correlation coefficients determined using SMA regression between PMF factors and emission tracers at AI. 15

16 Figure S5 : Correlation coefficients determined using SMA regression between PMF factors and emission tracers at AI. 16

17 Figure S6 : Correlation coefficients determined using SMA regression between PMF factors and emission tracers at AI. 17

18 (a) (b) (c) Figure S7 : Most probable source regions as determined by PSCF analysis for the ocean-derived factor identified using correlations to VOC tracers at (a) Appledore Island, (b) Chebogue Point, and (c) aboard R/V Ronald Brown. Wind sectors corresponding to events with the top 25th percentile of ocean-derived factor contribution are indicated on each plot. 18

19 (a) (c) (e) (b) (d) (f) Figure S8 : 3-day HYSPLIT back trajectories and the probability density distributions corresponding to the 75th percentile concentration of the ocean-derived factor at (a-b) Appledore Island, (c-d) Chebogue Point, and (e-f) aboard R/V Ronald Brown. 19

Phenols in Northeastern U.S. Aerosol Particles from. Lignin and its Products in Seawater

Phenols in Northeastern U.S. Aerosol Particles from Lignin and its Products in Seawater Ranjit Bahadur, Timothy Uplinger, Lynn M. Russell,, Barkley C. Sive, Steven S. Cliff, Dylan B. Millet, Allen Goldstein,