Analytical Methods Blog

Detection of selenium using graphite-based sensors

Researchers from the Manchester Metropolitan University reported the first example of graphite-based sensors to detect selenium in drinking water.
Selenium is a trace mineral nutrient essential as for all animals, but it is extremely toxic if the intake dose exceeds 400 µg per day. Both the European Union and United States Environmental Protection Agency (EPA) have set the limits for selenium in drinking water to of 10 µg/L and 50 µg/L respectively.

Today, the gold-based electrodes which are traditionally used to detect selenium are very expensive. With this work, Craig Banks and his group address the problem proposing a graphite based sensor to detect selenium in water. They fabricated special screen-printed graphite electrodes and detected low concentrations of selenium in their laboratory tap water, with a limit of detection which fell below those set by the EPA. According to the authors, this new graphite-based sensor could represent an appealing alternative to the gold based electrodes currently used.

To know more about this work, click on the link below. This paper will be free to read until January 24th.

Electroanalytical sensing of selenium(IV) utilising screen printed graphite macro electrodes
Athanasios V. Kolliopoulos ,  Jonathan P. Metters and Craig E. Banks
Anal. Methods, 2013, Advance Article
DOI: 10.1039/C2AY26041G

Take a look at the new detection methods described in these HOT articles in Analytical Methods! They include detection of medicinal products such as ginseng using near infrared spectral fingerprints and determination of lead in animal bone powder by X-ray fluorescence spectroscopy. These papers will be free to read until January 24th.

Expeditious identification and semi-quantification of Panax ginseng using near infrared spectral fingerprints and multivariate analysis
Juan Ricardo Lucio-Gutiérrez ,  Jordi Coello and S Maspoch
Anal. Methods, 2012, Accepted Manuscript
DOI: 10.1039/C2AY26235E

The feasibility of wavelength dispersive X-ray fluorescence spectrometry for the assessment of lead concentration in animal bone powder
José A. A. Brito ,  Inês I. B. Cavaleiro ,  Tânia A. P. Fernandes and Luísa M. L. Gonçalves
Anal. Methods, 2013, Advance Article
DOI: 10.1039/C2AY26455B

Determination of lead in animal bone powder

More articles for you to enjoy:

Novel pH sensor based on anthraquinone–ferrocene modified free standing gold nanowire array electrode
Louise Devlin ,  Mamun Jamal and Kafil Mahmood Razeeb
Anal. Methods, 2012, Accepted Manuscript
DOI: 10.1039/C2AY26264A

Combining enzymatic 18O-labeling and 2-D LC-MS/MS for study of protein interactions in primary T cells
Diana Lang ,  Sabine Anker ,  Benno Kuropka and Eberhard Krause
Anal. Methods, 2012, Accepted Manuscript
DOI: 10.1039/C2AY26298C

Detection of nitrite, iodate and bromate with Eu-POM sensor

Nitrite, iodate and bromate are commonly found in food and drinking water and they can play important roles in human health. Iodine compounds, for example, are crucial to the smooth running of the thyroid, while bromate is a by-product of water purification. However, the consumption of excessive amounts of these ions can cause serious health issues. Current methods of detecting nitrite, iodate and bromate largely rely on expensive spectroscopic equipment and time consuming chemical analysis.

Li-Hua Bi and Li-Xin Wu from Jilin University, China, have developed a novel detection method which utilises the electrochemistry and redox properties of a europium polyoxometalate (Eu-POM) sensor. The Eu-POM is electrochemically reduced, leading to luminescence quenching and a change in the solution from colourless to blue. The presence of oxidising nitrite, iodate and bromate ions reverses this process, affording discolouration and luminescence recovery. The colour change can be recycled infinitely, and measured using a UV-vis spectrometer. This sensor demonstrates a good linearity relationship between absorbance and concentration of NO₂^–, IO₃^– and BrO₃^–.

The simplicity of this method, along with high sensitivity and low detection limits, make it an attractive prospect for future use in the sensing of these ions in solution.

A novel detection of nitrite, iodate and bromate based on a luminescent polyoxometalate
Bin Wang,  Rui-Qi Meng,  Ling-Xiao Xu,  Li-Xin Wu and Li-Hua Bi
Anal. Methods, 2013, Advance Article
DOI: 10.1039/C2AY26217G

As well as the wonderful themed papers on Cosmetic Ingredients, we also have a number of brilliant non-themed articles in this latest issue. Topics covered include water analysis, hydrogen peroxide sensing, and CN^– testing in cells.

A simple and sensitive intramolecular charge transfer fluorescent probe to detect CN⁻ in aqueous media and living cells
Mohammad Shahid and Arvind Misra
Anal. Methods, 2013, 5,
DOI: 10.1039/C2AY25921D

Release of iodine from organic matter in natural water by K₂S₂O₈ oxidation for ¹²⁹I determination
Haijun Dang, Xiaolin Hou, Per Roos and Sven P. Nielsen
Anal. Methods, 2013, 5,
DOI: 10.1039/C2AY25958C

Aqueous synthesis of Ag⁺ doped CdS quantum dots and its application in H₂O₂ sensing
Lin Lin, Yaqiong Wen, Yanxia Liang, Na Zhang and Dan Xiao
Anal. Methods, 2013, 5,
DOI: 10.1039/C2AY26063H

These papers will be free to read until January 18th.

Detection of GHB in wine

γ-Hydroxybutyrate (GHB) is an odourless, tasteless compound sold illegally as a recreational drug under various names including ‘liquid ecstasy’. However it is more widely known as a date rape drug, causing catalepsy and short term memory loss when added to drinks.  Renato Zenobi and researchers at ETH Zürich report a new application of secondary electrospray ionisation (SESI) mass spectrometry for the detection of GHB in drinks and bodily fluids. The results were found to be consistent across different mass spectrometers and matrices. Both rapid and reliable, this method has the potential to prevent crimes by detecting drugs like GHB (and the structurally related compound GBL) in the headspace of a drink before it is consumed.

This article will be free to read until January 9th. Take a look now:

In situ detection of γ-hydroxybutyrate and γ-butyrolactone in drinks by secondary electrospray ionization
Christian Berchtold, Stefan Schmid, Lukas Meier and Renato Zenobi
Anal. Methods, 2013, Advance Article
DOI: 10.1039/C2AY26009C