Eu3+ as a dual probe for the determination of IL anion donor power: A combined luminescence spectroscopic and electrochemical approach

2014 ◽  
Vol 192 ◽  
pp. 191-198 ◽  
Author(s):  
Arash Babai ◽  
Gabriel Kopiec ◽  
Anastasia Lackmann ◽  
Bert Mallick ◽  
Slawomir Pitula ◽  
...  
2021 ◽  
Vol 2021 ◽  
pp. 1-14
Author(s):  
Chin Boon Ching ◽  
Jaafar Abdullah ◽  
Nor Azah Yusof

Palm oil is one of the major oils and fats produced in the world today. The quality of palm oil is crucial to be investigated, and one of the quality indices is free fatty acid (FFA) content. Therefore, in this study, an electrochemical approach for the determination of FFA has been explored as an alternative to replace the conventional method (titration method). The electrochemical method was developed based on electrochemically reduced graphene oxide (rGO) coupled with gold nanoparticles (AuNPs) deposited onto a screen-printed carbon electrode (SPCE) via drop-casting technique. The voltammetric behaviour of 2-methyl-1,4-naphthoquinone (VK3) in the presence of palmitic acid at the modified electrode was investigated in an acetonitrile/water mixture containing lithium perchlorate (LiClO4). The electrochemical detection of palmitic acid was based on the voltammetric reduction of VK3 to form the corresponding hydroquinone which is proportional to the concentration of palmitic acid. Under optimum conditions, the developed method showed a good linear relationship towards palmitic acid in the concentration ranging from 0.192 mM to 0.833 mM with the detection limit of 0.015 mM. The exploration of the developed system is expected to achieve high sensitivity and excellent selectivity towards the determination of FFA content in palm oil.


Author(s):  
A. Baniya ◽  
S. Thapa ◽  
E. Borquist ◽  
D. Bailey ◽  
D. Wood ◽  
...  

Hydrogen sulfide (H2S) is rapidly emerging as a biologically significant signaling molecule. In recent studies, sulfide level in blood or plasma has been reported to be in the concentration between 10 and 300 μM suggesting it acts in various diseases. This work reports progress on a new Lab-on-a-Chip (LOC) device for these applications. The uniquely designed, hand-held device uses advanced liberation chemistry that releases H2S from liquid sample and an electrochemical approach to detect sulfide concentration from the aqueous solution. The device itself consists of three distinct layers of Polydimethylsiloxane (PDMS) structures and a three electrode system for direct and rapid H2S concentration measurement. In this work specifically, the oxidation of sulfide at the gold (Au) and platinum (Pt.) electrodes has been examined. This is the first known application of electrochemical H2S sensing in an LOC application. The analytical utility and performance of the device has been assessed through direct detection using chronoamperometry (CA) scan and cyclic voltammetry (CV). An electrocatalytic sulfide oxidation signal has been recorded for sulfide concentration range vs, Ag/AgCl at different pH buffers at the trapping chamber. The calibration curve in the range 1 μM to 1 M was obtained using this electrode setup. The detection limit was found to be 0.1 μM. This device shows promise for providing fast and inexpensive determination of H2S concentration in aqueous samples.


2006 ◽  
Vol 153 (9) ◽  
pp. B352 ◽  
Author(s):  
Vincent Vignal ◽  
Nicolas Mary ◽  
Roland Oltra ◽  
Jéro^me Peultier

The Analyst ◽  
2021 ◽  
Author(s):  
Yudum Tepeli ◽  
Burak Ekrem Citil ◽  
U. Anik

In this study, an electrochemical approach for the determination of coronavirus disease (COVID-19) was developed. The biosensor system relied on the spike protein (S-protein) based infection mechanism of the virus...


The Analyst ◽  
2009 ◽  
Vol 134 (4) ◽  
pp. 748 ◽  
Author(s):  
Simon Ningsun Zhou ◽  
Ken D. Oakes ◽  
Mark R. Servos ◽  
Janusz Pawliszyn

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