Open AccessSample thickness and quantitative concentration measurements in Br K ‐edge XANES spectroscopy of organic materials
Author(s) -
Leri Alessandra C.,
Ravel Bruce
Publication year - 2014
Publication title -
journal of synchrotron radiation
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.172
H-Index - 99
ISSN - 1600-5775
DOI - 10.1107/s1600577514001283
Subject(s) - xanes , analytical chemistry (journal) , spectroscopy , k edge , normalization (sociology) , sample preparation , spectral line , detection limit , chemistry , materials science , environmental chemistry , chromatography , physics , quantum mechanics , astronomy , sociology , anthropology
While XANES spectroscopy is an established tool for quantitative information on chemical structure and speciation, elemental concentrations are generally quantified by other methods. The edge step in XANES spectra represents the absolute amount of the measured element in the sample, but matrix effects and sample thickness complicate the extraction of accurate concentrations from XANES measurements, particularly at hard X‐ray energies where the X‐ray beam penetrates deeply into the sample. The present study demonstrates a method of quantifying concentration with a detection limit approaching 1 mg kg −1 using information routinely collected in the course of a hard X‐ray XANES experiment. The XANES normalization procedure unambiguously separates the signal of the absorber from any source of background. The effects of sample thickness on edge steps at the bromine K ‐edge were assessed and an empirical correction factor for use with samples of variable mass developed.