Amy B. Dindal

Determination of exposure to environmental tobacco smoke in restaurant and tavern workers in one US city.

Approximately 173 subjects employed as waiters, waitresses, or bartenders in the Knoxville, TN, Standard Metropolitan Statistical Area collected a sample of air from their breathing zone while at their workplace for one shift. In addition, area samples were placed near the work spaces of many of the subjects. Collected samples were analyzed for respirable suspended particulate matter (RSPM), ultraviolet-absorbing and fluorescing particulate matter, solanesol, 3-ethenyl pyridine (3-EP), and nicotine. Saliva samples were collected from the subjects prior to and within 24 h following their work shift, to confirm their non-smoking status. The range of concentrations of environmental tobacco smoke (ETS) constituents encountered was considerable, e.g., for nicotine, from undetectable to more than 100 µg/m3. However, the highest RSP levels observed were considerably lower than OSHA workplace standards. Distributions of ETS concentrations suggest that there are two “ETS exposure” types of bartenders: those that work in single room bars and those that work in larger, multi-room restaurant/bars. Personal exposure to ETS of the former group was ca. 10× greater than those of the latter group, who were exposed to ETS levels more comparable to those encountered by wait staff. Exposure (concentration×duration) differences between wait staff and workers in other types of unrestricted smoking environments reported in other studies suggest that exposures in the restaurant environment may be more difficult to assess than originally considered. Salivary cotinine levels indicated that for those subjects living in smoking homes, ETS exposures outside the workplace are at least as important as those in the workplace.

MONITORING VOLATILE ORGANIC COMPOUNDS IN FLUE GAS USING DIRECT SAMPLING ION TRAP MASS SPECTROMETRY

Quantitative measurement of volatile organic compound concentrations in flue gas that has a high percentage of water vapor at low part-per-billion (ppb) to part-per-trillion levels represents a demanding analytical challenge. Direct sampling ion trap mass spectrometers developed at Oak Ridge National Laboratory are promising candidates to be developed into monitors of continuous emissions for these and other compounds at very low levels. Two direct sampling interfaces, a sorbent trap/thermal desorption interface and a continuous air monitor, have been tested in field studies of effluent from hazardous-waste incinerators. These interfaces demonstrate both an integrated, time-averaged and a raw gas, real-time approach to flue gas monitoring with detection limits in the ppb to sub-ppb range. The use of these interfaces for flue-gas monitoring with examples drawn from field tests are discussed.

Application of GC-HRMS and GC×GC-TOFMS to aid in the understanding of a dioxin assay's performance for soil and sediment samples.

There have been numerous attempts to correlate results obtained by gas chromatography-mass spectrometry (GC-MS) to alternative techniques such as immunoassays and bioassays for the analysis of dioxins in environmental samples. In spite of these efforts, uncertainties about the performance of these methods remain. Following a series of performance studies of various dioxin assays, an in-depth evaluation of sample extracts from the Procept Rapid Dioxin Assay was conducted to provide users with a clearer understanding of the differences in the assays results compared to traditional mass spectrometry. Two powerful analytical techniques [high-resolution mass spectrometry (HRMS) and two-dimensional gas chromatography coupled with time-of-flight mass spectrometry (GC×GC-TOFMS)] were used to provide a unique perspective about the assays underlying analytical performance. HRMS analyses demonstrated that the target dioxin and furans were consistently captured in the assays extracts. TOFMS analyses revealed that interferents in the sample extracts resulting from inconsistencies in the sample preparation process appear to be the primary factor contributing to the assays imprecision. The conclusion of this research was the assay results cannot be expected to correlate directly with HRMS and should only be utilized as a screening technique (e.g., to identify the relative ranking of contamination, to determine if samples are above/below threshold levels, or to monitor a cleanup) for environmental matrices such as soil and sediment.

Novel calibration technique for headspace analysis of semivolatile compounds

Vapor phase trap spiking methods have been developed and used for the analysis of volatile organic compounds. Because of their lower vapor pressures, this approach is not suitable for some semivolatile analytes, such as tributyl phosphate (TBP) and dibutyl butyl phosphonate (DBBP). A method was developed to independently quantify TBP and DBBP using a unique trap loading technique, and subsequent thermal desorption/gas chromatographic analysis. Modification of a gas chromatograph injection port allowed methanolic standards to be loaded onto sorbent traps quantitatively. The loaded calibration traps were then thermally desorbed and analyzed. Linearity, reproducibility, accuracy and method detection limits were established and will be reported for TBP and DBBP standards.