Validation of sulfur-gas standards, measurement of biogenic sulfur emissions from soils and vegetation, and the use of linear regression in analytical chemistry.

摘要

This dissertation covers four areas of work: (1) validation of sulfur-gas standards in the ppb/ppt concentration range, (2) measurement of biogenic sulfur emissions using dynamic enclosure systems, (3) use of linear regression for calibration and quantitation, and (4) use of linear regression when statistical error exists in the variables of both the x- and y-axes.;Sulfur-gas standards in the ppb/ppt range were based on low emission rate permeation devices. Gravimetric emission rates of these devices were validated via an interlaboratory comparison using three independently calibrated methods. The validation study also demonstrated the utility of a metal foil collection/flash desorption/flame photometric detection method (MFC/ FD/FPD) for rapidly determining emission rates of the permeation devices.;Biogenic sulfur emissions were measured as part of a collaborative field study which revisited sites examined in the EPRI-SURE field study. This work describes total sulfur-gas measurements made with an MFC/FD/FPD method at two sites: Ames, Iowa, and Celeryville, Ohio. Three different dynamic enclosures were used to measure emissions from two soil orders and various types of vegetation. Data from each soil/vegetation type showed good fit to a natural logarithm of sulfur flux vs. enclosure temperature model. Comparison with results from the SURE study showed much lower results for the present study.