330 likes | 487 Views
Ion Analysis. 2013 IMPROVE Steering Committee Meeting Park City, Utah October 8, 2013 Eva Hardison. Since the last meeting the RTI Ions Lab…. Added a new member, Tracy Dombek, to the Environmental Chemistry Department. Received and analyzed ~21,000 nylon filters for anions.
E N D
Ion Analysis 2013 IMPROVE Steering Committee Meeting Park City, Utah October 8, 2013 Eva Hardison
Since the last meeting the RTI Ions Lab… • Added a new member, Tracy Dombek, to the Environmental Chemistry Department. • Received and analyzed ~21,000 nylon filters for anions. • Purchased an SCP EasyPREP sample handler to automate part of the nylon filter extraction procedure. • Participated in the experimental inter-comparison of speciation laboratories conducted by NAREL in Jan/Feb 2013. • Performed research on wood smoke-impacted PM filters.
Newest member of the Environmental Chemistry Department • Tracy Dombek joined RTI’s Environmental Chemistry Department, bringing her experience in • Quality Assurance • Water analysis • Ion chromatography • Passive sampling/analysis • Formerly employed (2001 – 2013) by the Illinois State Water Survey, Champaign, IL, where she supported the NADP.
Ion Analysis • Nylon filters are received from UC-Davis in batches of 400 (8 trays of 50 each), with the sampling quarter indicated (e.g., A13, B13, C13, D13). • When filters are shipped, UC-Davis sends an email with an electronic master list of the samples in the batch. • RTI uses the list to prepare extraction tube labels and IC analysis queues. • The last batch in the quarter usually contains fewer than 400 samples and is indicated “end of quarter”. • RTI analyzes filters by batch.
Ion Data Reporting • RTI currently reports ion loadings, in µg, to UC-Davis by quarter (Excel .xlsxfile; ). • Ion data for the A13 Quarter (Mar, Apr, May 2013) were reported on 9/25/13. • Is there anything RTI can do to help with the data flow? • Report data by batch of 400 samples? • Report data by samples received in a given month? • Report data by samples collected in a given month?
Manual addition of deionized H2O • Analysts use electronic pipettes, serviced and calibrated annually by the manufacturer. • Each analyst has his/her own dedicated pipettes. • Disadvantages: • Labor intensive • Subject to human error
Automated addition of deionized H2O • SCP EasyPREP auto-handler • Computer-controlled • Holds 84 extraction tubes • Advantages: • Unattended operation • Labor/cost savings • Eliminates human error in dispensing H2O
Levoglucosan and S/SO4= Analyses of Wood Smoke – Impacted Filters • RTI performs PM2.5 chemical speciation analyses for the Alaska Department of Environmental Conservation (DEC). • For the winter of 2012, some filters showed very high loadings of PM (grav mass as high as 1623 ug/filter). • DEC requested that RTI expedite the analyses of 3 selected PM2.5 samples from the January 2013 sampling at the North Pole Fire 3 monitoring station. • RTI lab analysts noticed a strong wood odor on the filter samples, and as a part of our ongoing research, we were interested in confirming the presence of wood smoke. • RTI analyzed 4 samples for levoglucosan: 3 samples with high K+ loadings and 1 with insignificant K+to serve as a control.
Analyte Loadings on Selected Filters Impacted by Wood Smoke * RTI did not have field information, but assumed that quartz and nylon filters were from the same air sampling events. Levoglucosan loadings (analyzed in triplicate) on the 3 heavily loaded filters were strongly correlated with K+ loadings (R2 = 0.9876)
Comparison of K+ and Levoglucosan Loadings on Nylon and Quartz Filters As a quality assurance check, RTI analyzed the quartz filter samples for levoglucosanand K+ by extracting a small circular punch (0.53 cm2) and extracting it in 10 mL DI H2O.
S/SO4= Imbalance –Alaska Samples If all sulfur is present as soluble sulfate, the S/SO4= ratio would be 0.33.
Reconciliation of Sulfur/Sulfate Ratio * A 3-mL aliquot of the filter extract was treated with 50µL H2O2 For the selected filter, all extra sulfur was present in water soluble compounds which, when oxidized were converted to sulfate. However, it is possible that for other samples the non-sulfate sulfur may exist in non-soluble forms.
PM2.5 Sulfur/Sulfate Investigations RTI White Paper: • Levoglucosanand Sulfur/Sulfate Analysis of Selected Alaska Filter by Prakash Doraiswamy, Andrey Khlystov, Steven Walters, Eva Hardison and R.K.M. Jayanty, RTI International. Research Triangle Park, NC 27709 (submitted to Alaska Department of Environmental Conservation). Relevant Publications: • Tolocka, M. P. and B. Turpin, “Contribution of Organosulfur Compounds to Organic Aerosol Mass”, Environ. Sci. Technol. 2012, 46, 7978-7983. • Shakya, K. M. and R. E. Peltier, “Investigating Missing Sources of Sulfur at Fairbanks, Alaska”, Environ. Sci. Technol. 2013, 47, 9332-9338.
TRIN1 Extracts – Impacted by Wood Smoke6/11/08, 6/14/08, 6/17/08, 6/20/08, 6/26/08, 6/29/08, 7/2/08, 7/5/08, 7/8/08, 7/11/08
Examination of TRIN1 Chromatograms 6/14/08 thru 6/26/08:Unknown peaks at RT ~2.2 – 2.6 minutes observed on 6/26/08
Examination of TRIN1 Chromatograms 6/29/08 thru 7/8/08:Unknown peaks diminish during this period
LABE1 Extracts – Impacted by Wood Smoke7/24/13, 8/2/13, 7/21/13, 7/27/13, 7/30/13
Future Work • Identify the shoulder on the sulfate peak. • Separate the shoulder from the sulfate peak and determine the concentration.
Please visit our poster: Examination of PM2.5 Composition of Samples Impacted by Wildfires Tracy Dombek, Jessie Deal, Steven Walters++, David Hardison, Prakash Doraiswamy, James O’Rourke, Eva Hardison and R.K.M. Jayanty RTI International, Research Triangle Park, NC ++Currently with Division of Air Quality, NC Department of Environmental and Natural Resources, Raleigh, NC at the
Thanks to RTI/ECD Staff • Tracy Dombek • Jessie Deal • Prakash Doraiswamy • David Hardison • Jim O’Rourke • Dorie Pickett • Mel Richards • Christine Van Hise • Steven Walters* • *Currently with Division of Air Quality, NC DENR, Raleigh,NC