DEVELOPMENT AND APPLICATION OF THERMAL/OPTICAL- QUADRUPOLE MASS SPECTROMETRY FOR QUANTITATIVE ANALYSIS OF MAJOR PARTICULATE MATTER CONSTITUENTS.

Abstract

A new technique that couples a Desert Research Institute (DRI) Model 2001 Thermal Optical Carbon Analyzer (TOA) to an electron impaction ionization-quadrupole mass spectrometer (EI-QMS) is developed to analyze major chemical constituents of particulate matter (PM). This thermal desorption-mass spectrometry (TOA-QMS) technique is able to acquire particulate organics, sulfate, nitrate, and ammonium mass concentrations, as well as the ratios of oxygen (O), hydrogen (H), and nitrogen (N) to carbon (C), i.e., O/C, H/C, and N/C, as well as the ratio of organic matter (OM) to organic carbon (OC) in a single analysis. The analysis is conducted on archived quartz-fiber filter samples, which can cover large spatial and temporal scales. This thesis first describes the experimental setup, optimization, and calibration. Next, development of fragmentation table and characterization of ionization efficiency are documented. Finally, results of applying this technique to analyze real-world ambient samples are presented. The TD-MS technique is validated by comparing ion chromatography and thermal/optical carbon analyses for wintertime samples collected at Fresno, CA from December 2000 to February 2001.