Grantee Research Project Results

2005 Progress Report: Polar Organic Compounds in Fine Particles from the New York, New Jersey, and Connecticut Regional Airshed

EPA Grant Number: R832165
Title: Polar Organic Compounds in Fine Particles from the New York, New Jersey, and Connecticut Regional Airshed
Investigators: Mazurek, Monica
Institution: Rutgers
EPA Project Officer: Chung, Serena
Project Period: January 1, 2005 through December 31, 2007 (Extended to December 31, 2009)
Project Period Covered by this Report: January 1, 2005 through December 31, 2006
Project Amount: $449,150
RFA: Source Apportionment of Particulate Matter (2004) RFA Text | Recipients Lists
Research Category: Particulate Matter , Air Quality and Air Toxics , Air

Objective:

Fine particulate matter (PM) in urban atmospheres is composed of highly complex mixtures of organic compounds spanning large ranges of molecular weight and compound group classifications. Nearly 50 percent of the organic carbon mass collected as fine particles, however, cannot be analyzed using current molecular level mass spectrometric analytical methods (e.g., gas chromatography/mass spectrometry [GC/MS]) because of low volatility in the gas chromatographic system. Liquid chromatography/mass spectrometry (LC/MS) is an emerging technology to study polar organic compounds extracted from fine particles. The main objectives of this research project are to: (1) identify and measure the ambient abundances of polar organic compounds (acids and bases) found as PM_2.5 in the New York, New Jersey, and Connecticut regional airshed using LC/MS chemical analysis; (2) measure and identify both known and potential secondary organic aerosol source markers found within the fine particle acidic organic fraction; and (3) screen the Speciation of Organics for Appointment of PM_2.5 (SOAP) filter polar extracts for highly polar molecular markers from primary sources of urban fine particles.

Progress Summary:

The results to date expand the number of organic compounds with diverse functional groups that can be measured as fine particles in urban airsheds. This is important for identification and control of the sources of fine PM. In addition, improved chemical analysis of the organic fraction should assist with the broader U.S. Environmental Protection Agency (EPA) goals of understanding the relationship of PM chemical composition and its influence on air quality, human health, and the molecular components of secondary organic aerosol.

We continued to optimize the LC/MS instrument and to develop methods that target specific groups of known polar organic compounds which are measured as derivatives by GC/MS. Two important classes of secondary compounds are C3-C9 dicarboxylic acids and the benzenedicarboxylic acids. We increased the sensitivity of the atmospheric pressure photoionization (APPI) source by adding dopant solvent to the mobile phase as a post-column addition to detect and measure these compounds. The LC/MS results will be compared to analyses of the same diacids as methyl ester derivatives with GC/MS quantitation to determine which technique is better suited to routine quantitation of diacids and aromatic diacids in PM extract mixtures. We are developing an LC/MS method for the analysis of ambient carbonyl compounds in PM as 2,4-dinitrophenylhydrazene (DNPH) derivatives that is based on the California Air Resources Board (CARB) Method 1004 and the DNPH Mix 1 standard. The new, efficient high-performance liquid chromatography and LC/MS method has a 10-minute run time and requires only a single analytical column. Twelve of the 13 standard compounds in the CARB Mix 1 are fully resolved and can be quantified easily by ultraviolet detection. The method is a significant improvement in terms of resolution and analysis time compared to current EPA, CARB, and American Society for Testing and Materials DNPH protocols for atmospheric carbonyl compounds.

Levoglucosan, and to a lesser extent mannosan, galactosan, and 1,6-anhydro-b-D-glucofuranose, are important molecular markers of wood smoke emissions. We are preparing trimethylsilylimidazole (TMSI) derivatives of the mono- and disaccharides in the SOAP 2002-2003 network samples and have optimized the TMSI derivatization reaction for the low ng/m3 ambient concentrations expected for seasonal composites of the SOAP samples. We have studied the stability of the TMSI-alcohol derivatives and have determined acceptable precision if the samples are analyzed within 3 days of conversion. LC/MS does not require derivatives for these wood smoke markers in the polar extract mixtures. Therefore, this approach makes synthesis reactions unnecessary and does not depend on unstable target analytes. Direct analysis of wood smoke derivatives by LC/MS should facilitate quantitation of the wood smoke marker group for use in source apportionment modeling.

Finally, we have begun to develop LC/MS methods for the analysis of simple sugars in the SOAP 2002-2003 fine PM samples. Sugars such as monosaccharides (glucose, arabinose, fructose, galactose, mannose, arabitol, mannitol) and disaccharides (sucrose, maltose, mycose) are source indicators of biogenic organic carbon from macro- and microbiota. Monosaccharides and disaccharides are carbohydrates and are neutral polar and water-soluble organic compounds that can be analyzed by LC/MS as neutral compounds under positive mode source conditions.

Future Activities:

Research in Year 2 will continue to focus on the development of LC/MS quantitative analysis protocols, which target the polar molecular markers in the SOAP fine particle samples. These marker compounds are indicators of emission sources such as wood smoke, motor vehicles, and vegetation. Secondary compounds from smog chamber experiments will be studied as reference compounds from known systems and applied to the SOAP samples.

Journal Articles:

No journal articles submitted with this report: View all 15 publications for this project

Supplemental Keywords:

ambient air, atmosphere, sources, particulates, PAHs, organics, analytical, measurement methods, LC/MS, northeast, Atlantic coast, mid-Atlantic, New York, NY, New Jersey, NJ, Connecticut, CT, EPA Region 2,, RFA, Air, Ecosystem Protection/Environmental Exposure & Risk, Scientific Discipline, POLLUTANTS/TOXICS, particulate matter, Air Quality, Environmental Chemistry, Engineering, Chemistry, & Physics, Monitoring/Modeling, Air Pollution Effects, Atmospheric Sciences, air toxics, Chemicals, Environmental Engineering, Environmental Monitoring, aerosol particles, health effects, particulate emissions, particle size, air sampling, gas chromatography, mass spectrometry, emissions, measurement methods, airborne particulate matter, benzene, motor vehicle emissions, human exposure, air quality modeling, atmospheric particles, thermal desorption, particulate matter mass, air quality model, aerosol analyzers, particle phase molecular markers, air quality models, atmospheric particulate matter, particle dispersion, human health effects, PM 2.5, wood combustion

Progress and Final Reports:

Original Abstract

The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.