Low-Cost, High-Performance Sample Cell for X-Ray Spectroscopy of Solutions and Gels Made from Plastic Straw

Abstract

Low-cost tube-type sample cells for X-ray spectroscopy of solutions, sols, and gels were made from plastic straws. Energy-dispersive X-ray fluorescence (XRF) experiments showed that the X-ray transparency of the straw cells is ∼50% superior to that of quartz capillary cells for 6-7 keV XRF and is almost uniform over the entire range, allowing its use for position-dependent measurements. Wavelength-dispersive XRF experiments showed that the difference in the surface curvature between the straw cells and pellet samples leads to an apparent ∼1.5 eV shift of the Fe Kβ1,3 peak; however, chemical effects of Fe Kβ1,3 spectra can be studied if all the samples (including standards) are evenly set in the straw cells. Additionally, the application of the straw cell in studying precipitation band formation in gels was shown on two gel samples containing 0.004 M [Fe(CN)6] 3-/[Fe(CN)6] 2in 2 mass% κ-carrageenan and 0.040 M Fe 2+ /Fe 3+ in 1 mass% agarose, respectively.

Spontaneous precipitation pattern formation by crystallites of Mn–Fe-based Prussian blue analogues in agarose gel

“…Two different electrolytes are loaded in separate gel columns in a sample cell prepared from a plastic straw (a straw cell). 9 The longer gel column (∼30 mm) is placed at the bottom, where the periodic precipitation bands subsequently form. The shorter column (∼20 mm), on top, has a higher electrolyte concentration.…”

“…Straw cells containing either the agarose or water-glass gel samples were subsequently closed using styrene-resin stoppers covered with Teflon 9 (or Parafilm) and were allowed to stand at 25 °C for ∼10 d to form precipitation bands in the gels. The resultant precipitation patterns were photographed using a digital camera (IXY650, Canon, Japan).…”

Highly Resolved Mn Kβ Emission: A Potential Probe in Laboratory for Analysis of Ligand Coordination around Mn Atoms in Gels and Solutions

“…Powders of Mn, MnO, MnSO4•H2O, and KMnO4, as well as 0.50 M MnSO4 solution, were packed in sample cells prepared from plastic straws (straw cells) 32 for their Mn Kβ emission measurements.…”

“…1). A previously reported setup 32,33 was modified to form the setup for this study. The Cu Kα1 X-rays from an 18 kW generator (RU-300, Rigaku, Tokyo, Japan), operated at 40 kV and 150 mA, were focused within 0.5 mm in the horizontal direction by a Si (400) Johansson-type crystal monochromator (Saint-Gobain Crystals, Nemours, France).…”

X-ray Fluorescence Spectrometry

“…Hayashi et al made low-cost tube-type sample cells from plastic straws for the XRF spectrometry of solutions, sols, and gels. 10 High-resolution Fe Kβ1,3 spectra were obtained by using plastic straw cells for position-dependent measurements. The Prussianblue precipitation bands in gels were clearly detected as reaction-diffusion processes in hydro-gels.…”