Development of confocal X-ray fluorescence techniques for biological and archaeological applications

Choudhury, Sanjukta 1976-

Development of confocal X-ray fluorescence techniques for biological and archaeological applications

dc.contributor.committeeMember	Pickering, Ingrid J
dc.contributor.committeeMember	George, Graham N
dc.contributor.committeeMember	Coulthard, Ian
dc.contributor.committeeMember	Nichol, Helen
dc.contributor.committeeMember	Chapman, Dean
dc.contributor.committeeMember	Krone, Pat
dc.creator	Choudhury, Sanjukta 1976-
dc.date.accessioned	2020-02-11T20:28:04Z
dc.date.available	2020-02-11T20:28:04Z
dc.date.created	2016-04
dc.date.issued	2016-05-12
dc.date.submitted	April 2016
dc.date.updated	2020-02-11T20:28:04Z
dc.description.abstract	X-ray fluorescence imaging (XFI) is a versatile tool for determining spatial distributions of elements or elemental species within a variety of samples. A newer XFI variant, confocal X-ray fluorescence imaging (CXFI), shows significant promise since confocal detection facilitates important advantages such as three-dimensionally resolved elemental investigation, preservation of sample integrity and higher sensitivity. Additionally, a readily available extension of CXFI, confocal X-ray absorption spectroscopy (CXAS), allows determination of elemental speciation within a specific localized volume element. To enable direct visualization of three-dimensional elemental distribution and speciation in intact biological samples without staining or thinning, this thesis aimed at developing CXFI and CXAS for biological and archaeological applications. CXFI and CXAS technique development included installing and refining the polycapillary based setup at beamline 20ID-B, Advanced Photon Source (APS), USA, and verifying the feasibility of different configurations through select measurements. In addition, a novel X-ray detection focusing optic, the spoked channel array (SCA) recently developed at the Cornell High Energy Synchrotron Source (CHESS), USA, was implemented to provide superior spatial resolution. CXFI and CXAS were used to study the following scientific problems: a) Embryonic exposure to elevated selenium in zebrafish: The localization and chemical form of maternally transferred selenium were studied in an early developmental stage of life to understand the effect of exposure. b) Highly localized Fe speciation within intact corrosion layer in antique stained glass: SCA derived CXAS was employed to determine iron speciation in an antique stained glass sample from 13th century Paderborn Cathedral, Germany to aid the study of cleaning methods used in restoration. c) Differentiating diagenesis from biogenicity: Archaeological bone samples from the Royal Naval Hospital Cemetery (c. A.D. 1793-1822), Antigua were studied in an attempt to distinguish between diagenetic and biogenic lead uptake. Systematic comparisons of conventional XFI with polycapillary and SCA-based CXFI showed that lateral spatial resolution was remarkably improved with SCA optics. This research facilitated incorporating CXFI and CXAS at beamline 20ID-B, APS and establishing SCA optics as a valuable addition to the confocal X-ray detection toolkit. These capabilities will be implemented at the BioXAS imaging beamline at the Canadian Light Source.
dc.format.mimetype	application/pdf
dc.identifier.uri	http://hdl.handle.net/10388/12591
dc.subject	Synchrotron
dc.subject	X-ray fluorescence imaging
dc.subject	confocal X-ray fluorescence imaging
dc.subject	confocal X-ray absorption spectroscopy
dc.subject	polycapillary
dc.subject	spoked channel array
dc.subject	selenium
dc.subject	zebrafish
dc.subject	antique stained glass
dc.subject	corrosion layer
dc.subject	archaeological human bone
dc.subject	lead
dc.subject	diagenesis
dc.title	Development of confocal X-ray fluorescence techniques for biological and archaeological applications
dc.type	Thesis
dc.type.material	text
thesis.degree.department	Geological Sciences
thesis.degree.discipline	Interdisciplinary Studies
thesis.degree.grantor	University of Saskatchewan
thesis.degree.level	Doctoral
thesis.degree.name	Doctor of Philosophy (Ph.D.)