MS, University of Cincinnati, 2002, Medicine : Environmental Health Sciences

Purpose. The purpose of this research was to determine the practicality of using airborne lead measurements obtained with field portable x-ray fluorescence (XRF) technology to manage worker protection programs. The NITON® XL-700 Series XRF was used to measure airborne lead samples from the U.S. Coast Guard Barque EAGLE while undergoing repairs at the Coast Guard Shipyard. Lead-based paint was used extensively during construction of EAGLE, which was completed in 1936 in Hamburg, Germany. Methods: 47 airborne lead samples were collected in 37 mm cassettes on mixed cellulose ester filters over two weeks. Twenty (20) personal and twenty-seven (27) area samples were obtained. Samples collected during week one were analyzed by XRF the following Sunday, when no work was scheduled on EAGLE. Samples obtained during week two were analyzed daily with field portable XRF. The samples were analyzed using NIOSH Method 7702, Lead by Field Portable XRF to determine lead mass. Using known air volume and lead mass, airborne lead concentration was calculated. To verify instrument performance, the samples were later analyzed by NIOSH Method 7082, Lead by Flame AAS. Results: The range of airborne lead concentrations was 8 to 939 μg/m 3 . With daily monitoring by field portable XRF, airborne lead concentration was reduced 77 percent from week one to week two. The average concentration was 176.9 μg/m 3 during the first week, while the average was 41.3 μg/m 3 during the second. With the exposure data gathered in near real-time, workers reduced concentration by implementing controls including vacuum equipped tools and improved ventilation. On twelve (12) occasions during week one, workers engaged in jobs that produced airborne lead concentrations that exceeded the action level. During week two, when daily monitoring by field portable XRF was instituted, workers exceeded the action level six (6) times. Conclusions: Provided that a sheltered workspace with minimal distractions is available to (open full item for complete abstract)

Committee: Dr. C. Scott Clark (Advisor) Subjects:

Master of Science (MS), Ohio University, 2009, Chemistry and Biochemistry (Arts and Sciences)

Ongoing environmental, forensic, and homeland security needs dictate the necessity for rapid, selective, and on-site mass spectrometric analysis of unknown substances. Current efforts in rendering mass spectrometers field portable are examined, with special attention given to the inherent challenges, advantages, and disadvantages of miniaturization in each case. Current trends and developments in field ambient ion sources are also investigated.With contemporary developments in mind, an alternative paradigm in miniature mass spectrometric analysis is presented. The inherently miniature Loeb-Eiber mass filter presents unique possibilities and advantages for mass spectrometric systems. Initial testing and development of a Loeb-Eiber mass filter is reported along with the development of a testing interface. Special attention is given to the observed performance of the filter and to its current challenges. Directions for future research are proposed to address current difficulties.

Committee: Glen P. Jackson PhD (Advisor); Ken Brown PhD (Committee Member); Hao Chen PhD (Committee Member) Subjects: Analytical Chemistry; Chemistry