scholarly journals Alexdrandrite Effects and Pseudosymmetry in Aluminum Oxalates

2014 ◽  
Vol 70 (a1) ◽  
pp. C1017-C1017
Author(s):  
Ruthairat Nimthong ◽  
Matthias Zeller ◽  
Patimaporn Sungnoi ◽  
Sumpun Wongnawa ◽  
Chaveng Pakawatchai

Three chromium doped potassium aluminum oxalates, (K3[Al0.95Cr0.05(C2O4)3]·3H2O) "Blue", (K2/3Na7/3[Al0.95Cr0.05(C2O4)3]·4H2O) "RedCubic", and (K18{Na[Al0.964Cr0.036(C2O4)3]6}Cl·18H2O) "Red-Hexagonal" were prepared from aqueous solutions of K3[Cr(C2O4)3]·3H2O, K3[Al(C2O4)3]·3H2O and NaCl, and their solid state and solution properties were rationalized from their crystal structures, analysis data and solid state and solution UV-vis spectra. Crystals of "RedCubic" are characterized by a metrically cubic I-centered unit cell, but do have actual tetragonal symmetry derived by ordering of sodium and potassium ions not compatible with the apparent cubic symmetry. Results of 13C-NMR, EPMA/EDX, SC-XRD, and UV-Vis spectroscopies are discussed in relation to the compound's structures and color behavior. In aqueous solution RedCubic and Blue show the same greenish purple color and identical electronic absorption peaks. In the solid state, they have different colors and show slightly different absorption peaks. Their color behavior as well as the Alexandrite color-change effect observed in the two Red crystals are rationalized based on the compounds' absorption peaks.

Biosensors ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 109
Author(s):  
Li-Da Chen ◽  
Wei-Jhen Wang ◽  
Gou-Jen Wang

This study aimed to develop simple electrochemical electrodes for the fast detection of chloride, sodium and potassium ions in human serum. A flat thin-film gold electrode was used as the detection electrode for chloride ions; a single-piece type membrane based solid-state ion-selective electrode (ISE), which was formed by covering a flat thin-film gold electrode with a mixture of 7,7,8,8-tetracyanoquinodimethane (TCNQ) and ion-selective membrane (ISM), was developed for sodium and potassium ions detection. Through cyclic voltammetry (CV) and square-wave voltammetry (SWV), the detection data can be obtained within two minutes. The linear detection ranges in the standard samples of chloride, sodium, and potassium ions were 25–200 mM, 50–200 mM, and 2–10 mM, with the average relative standard deviation (RSD) of 0.79%, 1.65%, and 0.47% and the average recovery rates of 101%, 100% and 96%, respectively. Interference experiments with Na+, K+, Cl−, Ca2+, and Mg2+ ions demonstrated that the proposed detection electrodes have good selectivity. Moreover, the proposed detection electrodes have characteristics such as the ability to be prepared under relatively simple process conditions, excellent detection sensitivity, and low RSD, and the detection linear range is suitable for the Cl−, Na+ and K+ concentrations in human serum.


2021 ◽  
Author(s):  
Li-Da Chen ◽  
Gou-Jen Wang

Abstract This study aimed to develop simple electrochemical electrodes for the fast detection of chlorine, sodium, and potassium ions in human serum. A flat thin-film gold electrode was used as the detection electrode for chloride ions; a solid-state ion-selective electrode (ISE), which was formed by covering a flat thin-film gold electrode with a mixture of 7,7,8,8-tetracyanoquinodimethane (TCNQ) and ion-selective membrane (ISM), was developed for sodium and potassium ions detection. Through cyclic voltammetry (CV) and square-wave voltammetry (SWV), the detection data can be obtained within two minutes. The linear detection ranges in the standard samples of chlorine, sodium, and potassium ions were 25–200 mM, 50–200 mM, and 2–10 mM, with the average relative standard deviation (RSD) of 0.79%, 1.65%, and 0.47% and the average recovery rates of 101%, 100%, and 96% respectively. Interference experiments using normal concentrations of Na+, K+, Cl−, Ca2+, and Mg2+ in human blood demonstrated that the proposed detection electrodes have good selectivity. Moreover, the proposed detection electrodes have characteristics such as the ability to be prepared under relatively simple process conditions, excellent detection sensitivity, and low RSD, and the detection linear range is suitable for the Cl−, Na+, and K+ concentrations in human serum.


2021 ◽  
Author(s):  
Long Cao ◽  
Han-Ling Guo ◽  
Rui Lian Lin ◽  
Li-Fei Tian ◽  
Zhi-Hua Zhang ◽  
...  

Using multiple techniques, this work studied the binding behaviors of decamethylcucurbit[5]uril (Me10Q[5]) with o-, m- and p-phenylenediamine (PDA) isomers both in solid state and in aqueous solution. Experimental data indicate...


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