The effects of accumulated refractory particles and the peak inert mode temperature on semi-continuous organic carbon and elemental carbon measurements during the CAREBeijing 2006 campaign

Abstract. We thoroughly characterized a system for thermal separation of organic carbon (OC) and elemental carbon (EC) for subsequent radiocarbon analysis. Different organic compounds as well as ambient aerosol filter samples were introduced into an oven system and combusted to CO2 in pure O2. The main objective was to test which combustion times and temperatures are best suited to separate OC and EC. The final separation step for OC was combustion at 360 °C for 15 min. Combustion at this temperature proved enough to remove several organic test substances from the filter (including high molecular weight humic acid) but did not remove substantial amounts of EC. For isolation of EC, OC first needs to be completely removed from the filter. This was achieved by water extraction of the filter, followed by combustion of the water insoluble OC at 360 °C and combustion at an intermediate temperature step of 2 min at 450 °C. This last step removed the most refractory OC together with some EC. Finally, the remaining EC was combusted to CO2 at 650 °C. The recovery of black carbon after the intermediate 450 °C step was approximately 80%. Several tests provided strong evidence that OC was removed efficiently during the intermediate temperature step: (i) brown carbon, indicative of refractory OC, was removed; (ii) the fraction modern of EC did not decrease significantly if the temperature of the intermediate step was further increased. Based on tests with various organic compounds, we estimated that charred organic carbon could contribute 4–8% to an elemental carbon sample that was isolated according to our method.

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A predictive model for elemental carbon, organic carbon and total carbon based on laser induced breakdown spectroscopy measurements of filter-collected diesel particulate matter

Spectrochimica Acta Part B Atomic Spectroscopy ◽

10.1016/j.sab.2020.105871 ◽

2020 ◽

Vol 168 ◽

pp. 105871

Author(s):

R.P. McLaughlin ◽

D.A. Parks ◽

A.I. Grubb ◽

G.S. Mason ◽

A.L. Miller

Keyword(s):

Particulate Matter ◽

Organic Carbon ◽

Predictive Model ◽

Elemental Carbon ◽

Total Carbon ◽

Laser Induced Breakdown Spectroscopy ◽

Diesel Particulate Matter ◽

Diesel Particulate ◽

Breakdown Spectroscopy ◽

Laser Induced Breakdown

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High contributions of fossil sources to more volatile organic aerosol

Atmospheric Chemistry and Physics ◽

10.5194/acp-19-10405-2019 ◽

2019 ◽

Vol 19 (15) ◽

pp. 10405-10422 ◽

Cited By ~ 2

Author(s):

Haiyan Ni ◽

Ru-Jin Huang ◽

Junji Cao ◽

Wenting Dai ◽

Jiamao Zhou ◽

...

Keyword(s):

Organic Carbon ◽

Elemental Carbon ◽

Organic Aerosol ◽

Formation Mechanisms ◽

Formation Processes ◽

Combustion System ◽

Relative Contribution ◽

Custom Made ◽

Volatile Organic ◽

Volatile Carbon

Abstract. Sources of particulate organic carbon (OC) with different volatility have rarely been investigated, despite the significant importance for better understanding of the atmospheric processes of organic aerosols. In this study we develop a radiocarbon-based (14C) approach for source apportionment of more volatile OC (mvOC) and apply to ambient aerosol samples collected in winter in six Chinese megacities. mvOC is isolated by desorbing organic carbon from the filter samples in helium (He) at 200 ∘C in a custom-made aerosol combustion system for 14C analysis. Evaluation of this new isolation method shows that the isolated mvOC amount agrees very well with the OC1 fraction (also desorbed at 200 ∘C in He) measured by a thermal–optical analyzer using the EUSAAR_2 protocol. The mvOC, OC and elemental carbon (EC) of 13 combined PM2.5 samples in six Chinese cities are analyzed for 14C to investigate their sources and formation mechanisms. The relative contribution of fossil sources to mvOC is 59±11 %, consistently larger than the contribution to OC (48±16 %) and smaller than that to EC (73±9 %), despite large differences in fossil contributions in different cities. The average difference in the fossil fractions between mvOC and OC is 13 % (range of 7 %–25 %), similar to that between mvOC and EC (13 %, with a range 4 %–25 %). Secondary OC (SOC) concentrations and sources are modeled based on the 14C-apportioned OC and EC and compared with concentrations and sources of mvOC. SOC concentrations (15.4±9.0 µg m−3) are consistently higher than those of mvOC (3.3±2.2 µg m−3), indicating that only a fraction of SOC is accounted for by the more volatile carbon fraction desorbed at 200 ∘C. The fossil fraction in SOC is 43 % (10 %–70 %), lower than that in mvOC (59 %, with a range of 45 %–78 %). Correlation between mvOC and SOC from nonfossil sources (mvOCnf vs. SOCnf) and from fossil sources (mvOCfossil vs. SOCfossil) is examined to further explore sources and formation processes of mvOC and SOC.

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Sources of PM<sub>2.5</sub> carbonaceous aerosol in Riyadh, Saudi Arabia

10.5194/acp-2017-829 ◽

2017 ◽

Author(s):

Qijing Bian ◽

Badr Alharbi ◽

Mohammed M. Sharee ◽

Tahir Husai ◽

Mohammad J. Pasha ◽

...

Keyword(s):

Saudi Arabia ◽

Air Quality ◽

Organic Carbon ◽

Pollution Control ◽

Elemental Carbon ◽

Control Strategies ◽

Continuous Method ◽

Carbonaceous Aerosol ◽

Abstract Knowledge ◽

The City

Abstract. Knowledge of the sources of carbonaceous aerosol affecting air quality in Riyadh, Saudi Arabia is limited, but needed for the development of pollution control strategies. We conducted sampling of PM2.5 from April to September, 2012 at various sites in the city, and used a thermo-optical semi-continuous method to quantify the organic carbon (OC) and elemental carbon (EC) concentrations. The average OC and EC concentrations were 4.7 ± 4.4 and 2.1 ± 2.5 μg m

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Isotopic composition of organic carbon and elemental carbon in PM2.5 in Hangzhou, China

Chinese Science Bulletin ◽

10.1007/s11434-007-0347-1 ◽

2007 ◽

Vol 52 (17) ◽

pp. 2435-2437 ◽

Cited By ~ 6

Author(s):

Gang Liu ◽

XuXian Zhang ◽

WeiLin Teng ◽

Hui Yang

Keyword(s):

Organic Carbon ◽

Isotopic Composition ◽

Elemental Carbon

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Fossil and non-fossil sources of organic carbon (OC) and elemental carbon (EC) in Göteborg, Sweden

Atmospheric Chemistry and Physics ◽

10.5194/acp-9-1521-2009 ◽

2009 ◽

Vol 9 (5) ◽

pp. 1521-1535 ◽

Cited By ~ 168

Author(s):

S. Szidat ◽

M. Ruff ◽

N. Perron ◽

L. Wacker ◽

H.-A. Synal ◽

...

Keyword(s):

Organic Carbon ◽

Elemental Carbon ◽

Latin Hypercube Sampling ◽

Water Soluble ◽

Total Carbon ◽

Rural Site ◽

Urban Site ◽

Winter Period ◽

Back Trajectories ◽

Wood Burning

Abstract. Particulate matter was collected at an urban site in Göteborg (Sweden) in February/March 2005 and in June/July 2006. Additional samples were collected at a rural site for the winter period. Total carbon (TC) concentrations were 2.1–3.6 μg m−3, 1.8–1.9 μg m−3, and 2.2–3.0 μg m−3 for urban/winter, rural/winter, and urban/summer conditions, respectively. Elemental carbon (EC), organic carbon (OC), water-insoluble OC (WINSOC), and water-soluble OC (WSOC) were analyzed for 14C in order to distinguish fossil from non-fossil emissions. As wood burning is the single major source of non-fossil EC, its contribution can be quantified directly. For non-fossil OC, the wood-burning fraction was determined independently by levoglucosan and 14C analysis and combined using Latin-hypercube sampling (LHS). For the winter period, the relative contribution of EC from wood burning to the total EC was >3 times higher at the rural site compared to the urban site, whereas the absolute concentrations of EC from wood burning were elevated only moderately at the rural compared to the urban site. Thus, the urban site is substantially more influenced by fossil EC emissions. For summer, biogenic emissions dominated OC concentrations most likely due to secondary organic aerosol (SOA) formation. During both seasons, a more pronounced fossil signal was observed for Göteborg than has previously been reported for Zurich, Switzerland. Analysis of air mass origin using back trajectories suggests that the fossil impact was larger when local sources dominated, whereas long-range transport caused an enhanced non-fossil signal. In comparison to other European locations, concentrations of levoglucosan and other monosaccharide anhydrides were low for the urban and the rural site in the area of Göteborg during winter.

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Better constraints on sources of carbonaceous aerosols using a combined <sup>14</sup>C – macro tracer analysis in a European rural background site

Atmospheric Chemistry and Physics ◽

10.5194/acp-11-5685-2011 ◽

2011 ◽

Vol 11 (12) ◽

pp. 5685-5700 ◽

Cited By ~ 100

Author(s):

S. Gilardoni ◽

E. Vignati ◽

F. Cavalli ◽

J. P. Putaud ◽

B. R. Larsen ◽

...

Keyword(s):

Organic Carbon ◽

Biomass Burning ◽

Elemental Carbon ◽

Total Carbon ◽

Carbonaceous Aerosol ◽

Back Trajectory ◽

Po Valley ◽

Background Site ◽

Potential Source ◽

Source Contributions

Abstract. The source contributions to carbonaceous PM2.5 aerosol were investigated at a European background site at the edge of the Po Valley, in Northern Italy, during the period January–December 2007. Carbonaceous aerosol was described as the sum of 8 source components: primary (1) and secondary (2) biomass burning organic carbon, biomass burning elemental carbon (3), primary (4) and secondary (5) fossil organic carbon, fossil fuel burning elemental carbon (6), primary (7) and secondary (8) biogenic organic carbon. The mass concentration of each component was quantified using a set of macro tracers (organic carbon OC, elemental carbon EC, and levoglucosan), micro tracers (arabitol and mannitol), and 14C measurements. This was the first time that 14C measurements covered a full annual cycle with daily resolution. This set of 6 tracers, together with assumed uncertainty ranges of the ratios of OC-to-EC, and the reference fraction of modern carbon in the 8 source categories, provides strong constraints to the source contributions to carbonaceous aerosol. The uncertainty of contributions was assessed with a Quasi-Monte Carlo (QMC) method accounting for the variability of OC and EC emission factors, the uncertainty of reference fractions of modern carbon, and the measurement uncertainty. During winter, biomass burning composed 64 % (±15 %) of the total carbon (TC) concentration, while in summer secondary biogenic OC accounted for 50 % (±16 %) of TC. The contribution of primary biogenic aerosol particles was negligible during the entire year. Moreover, aerosol associated with fossil sources represented 27 % (±16 %) and 41 % (±26 %) of TC in winter and summer, respectively. The contribution of secondary organic aerosol (SOA) to the organic mass (OM) was significant during the entire year. SOA accounted for 30 % (±16 %) and 85 % (±12 %) of OM during winter and summer, respectively. While the summer SOA was dominated by biogenic sources, winter SOA was mainly due to biomass burning and fossil sources. This indicates that the oxidation of semi-volatile and intermediate volatility organic compounds co-emitted with primary organics is a significant source of SOA, as suggested by recent model results and Aerosol Mass Spectrometer measurements. Comparison with previous global model simulations, indicates a strong underestimate of wintertime primary aerosol emissions in this region. The comparison of source apportionment results in different urban and rural areas showed that the sampling site was mainly affected by local aerosol sources during winter and regional air masses from the nearby Po Valley in summer. This observation was further confirmed by back-trajectory analysis applying the Potential Source Contribution Function method to identify potential source regions.

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Organic carbon and elemental carbon in Asia: A review from 1996 to 2006

Journal of Hazardous Materials ◽

10.1016/j.jhazmat.2007.09.036 ◽

2008 ◽

Vol 150 (2) ◽

pp. 231-237 ◽

Cited By ~ 14

Author(s):

Guor-Cheng Fang ◽

Yuh-Shen Wu ◽

Te-Yen Chou ◽

Chen-Zheng Lee

Keyword(s):

Organic Carbon ◽

Elemental Carbon

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