Fast and simple selenium speciation by solid phase extraction and laser-induced breakdown spectroscopy

Abstract

The chemical properties including toxicity of selenium depend on the concentration and chemical structure present in the natural environment. Inorganic selenium is more toxic than organic selenium; thus, the accurate determination of inorganic selenium in various sample has been needed. HG-AAS, HPLC-ICP-MS, and GC-MS are the current methods for the determination of inorganic selenium. However, these methods have the disadvantage of expensive equipment, complicated sample preparation, and long analysis time. LIBS coupled with ion exchange membrane was used for the determination of inorganic selenium. The detection limit of inorganic selenium by the analytical method was 11.21 mg/kg, and the recoveries of 50 and 100 mg/kg Se(VI) were 98.5 % and 101.80 %, respectively. The speciation method is cost-effective, simple, and not labor intensive for the quantitation of inorganic selenium.

An Interactive Simulation and Visualization Tool for Conventional and Aberration-Corrected Transmission Electron Microscopy

“…These examples can be viewed as a brief guideline for using the CTFscope. Two examples are given here to evaluate the CTFscope, in which the calculated images are compared to the figures in the published papers [9,12].…”

“…The second example is a comparison of the results calculated using the CTFscope with other software, for example, exCTF. Figure 4 of reference [9] was calculated based on experimental data obtained from an AC-TEM device and compared to a calculated graph from the commercial GUI program (CETCOR, CEOS). Figure 9a shows a CTF 2D graph calculated using the CTFscope (Figure 9b–9d) using the same aberration parameters in Figure 4 of reference [9].…”

“…Software programs and scripts for simulation and visualization of the CTF have been developed and are available in the public domain for conventional TEM [6–8] and AC-TEM [9]. Two were launched nearly twenty years ago [6,7], and the script was updated in 2017 [8].…”

“…Two were launched nearly twenty years ago [6,7], and the script was updated in 2017 [8]. Lee et al [9] recently developed the extended CTF (exCTF) simulator to perform the primary and extensive CTF calculation designed to obtain more information than earlier software. Inspired by previous software on the CTF, we developed the CTFscope as a simulation and visualization tool of the CTF with a user-friendly interface for conventional TEM and AC-TEM.…”

Speciation of inorganic selenium in natural water by in situ solid-phase extraction using functionalized silica

“…Preconcentration at the stage of sample preparation made it possible not only to separate the selenium species, but also to eliminate the interfering effect of matrix components before atomic spectrometric or mass spectrometric determination. Various adsorbents have been used to separate selenium species: anion-exchange membranes Empore™, 20 resins, 21,22 functionalized magnetic adsorbents, 23 chemically modied alumina and silica, [24][25][26] and carbon nanotubes. [27][28][29] Separation of selenium species is based on differences in chemical behavior of Se(VI) and Se(IV).…”