X-Ray Fluorescence under Grazing Incidence

Total external reflection fluorescence and grazing incidence x-ray fluorescence are techniques that rely on standing waves created by the reflector to excite the fluorescent emission from small amounts of analytes. Formally, the sample under investigation only perturbs the wavefields slightly resulting in no matrix (absorption) effects and well-defined wavefields. The transition to more bulk-like systems in which this approximation is violated is poorly understood. In this proposal we aim to explore the interface between TXRF and XRF performed under grazing incidence. Our study will explore the experimental conditions and ranges of validity. The data will be an essential part of a recently launched VAMAS study to explore the feasibility of using XRF under grazing incidence to quantify airborne particulate matter as well as a new work proposal (on 23971.2.2) for an ISO standard “Analysis of air PM filters by XRF under grazing incidence” launched within the ISO TC201 committee.