Remarkable chemical characterization using advanced X-ray spectroscopy

Posted on 2017-10-18 in Events
Oct 23, 2017

Please join us for a Graduate Student Seminar on Monday October 23 at 10:30 am at the CLS in meeting rooms 2068A and 2068B presented by Susan Nehzati, PhD Candidate:

TOPIC: Remarkable chemical characterization using advanced X-ray spectroscopy

ABSTRACT:

High energy resolution fluorescence detection (HERFD) is an advanced X-ray based spectroscopic method that can reveal remarkable structural and bonding information of chemical compounds. HERFD offers the chemical sensitivity to detect and identify various chemical forms and is suited for a range of in situ matrices in the nano-molar range. Improved energy resolution can be achieved with an experimental setup that uses Bragg optics to provide point-to-point geometry to reduce signal from background scattering. Analysis using a multicrystal spectrometer preferentially reflects with highly selective energy resolution a fraction of the emission line of interest and accordingly vastly improves signal-to-noise.

Here we report the improved energy resolution of HERFD X-ray absorption spectroscopy (XAS) compared to conventional XAS of multiple selenium and mercury standard compounds. As well, results demonstrate the exceptional chemical sensitivity to natural trace levels of selenium and mercury in wild fish as a testament to the strength of this method. This technique can be applied to any element of interest and along with its enhanced chemical sensitivity will fortify the use of synchrotron X-ray sources in advanced chemical characterization.