Analytical Methods Blog

Take a look at this great list of selected HOT articles recently published in Analytical Methods! Topics include nanoparticle-based colorimetric anticancer drug detection methods and ultra performance liquid chromatography-tandem mass spectrometry for multiple bile acids detection.

Check out also the new review by Edward Randviir and Craig Banks on electrochemical impedance spectroscopy. All these papers will be free for you to read until February 18th. 

Electrochemical Impedance Spectroscopy: An Overview of Bioanalytical Applications
Edward P Randviir and Craig E Banks
Anal. Methods, 2013, Accepted Manuscript
DOI: 10.1039/C3AY26476A

Application of an electronic tongue towards the analysis of brandies
Xavier Cetó ,  Matias Llobet ,  Joan Marco and Manel del Valle
Anal. Methods, 2013, Advance Article
DOI: 10.1039/C2AY26066B

Potential of solid sampling high-resolution continuum source graphite furnace atomic absorption spectrometry to monitor the Ag body burden in individual Daphnia magna specimens exposed to Ag nanoparticles
Martín Resano ,  Ana C. Lapeña and Miguel A. Belarra
Anal. Methods, 2013, Advance Article
DOI: 10.1039/C2AY26456K

Self-powered herbicide biosensor utilizing thylakoid membranes
Michelle Rasmussen and Shelley D. Minteer
Anal. Methods, 2013, Advance Article
DOI: 10.1039/C3AY26488B

Quantification of Multiple Bile Acids in Uninephrectomized Rats Using Ultra-Performance Liquid Chromatography-Tandem Mass Spectrometry
Carlos A Penno ,  Denis Arsenijevic ,  Thierry Da Cunha ,  Gerd A Kullak-Ublick ,  Jean-Pierre Montani and A Odermatt
Anal. Methods, 2013, Accepted Manuscript
DOI: 10.1039/C3AY26520J

Colorimetric anticancer drug detection by gold nanoparticle-based DNA interstrand cross-linking
Xiaoji Xie ,  Renren Deng ,  Feng Liu ,  Wei Xu ,  Sam Fong Yau Li and Xiaogang Liu
Anal. Methods, 2013, Advance Article
DOI: 10.1039/C3AY26422J

Trace concentrations of cadmium in water, soil and industrial settings can have devastating health effects if not detected. Furthermore, measuring accurate cadmium levels in these complex samples is hindered by signal interference from other metals such as tin, molybdenum, and zirconium.

Robert Thompson and Steven Christopher in the United States developed a four-step separation methodology to remove these metals, and then used inductively coupled plasma mass spectrometry to measure cadmium concentrations. For this procedure, commercially available solid phase extraction cartridges isolate most of cadmium and strong ion exchange chromatography removes tin and molybdenum. This unique sample preparation facilitates the detection of low cadmium concentrations in marine sediment and rice flour which contain high levels of tin and molybdenum respectively.

Determination of cadmium in samples containing molybdenum and tin

To know more about this study, please access the link below. This paper will be free to read until February 18th.

Novel separation for the determination of cadmium by isotope dilution ICP-MS in samples containing high concentrations of molybdenum and tin
Robert Q. Thompson and Steven J. Christopher
Anal. Methods, 2013, Advance Article
DOI: 10.1039/C2AY26212F

Mandel's test for goodness of fit

The economic and time constraints that limit the collection of calibration data mean that analytical chemists rely on robust statistical tests for linearity to support the accuracy of their findings. Mandel’s test was first proposed in 1964 and despite being simplified and suggested by IUPAC in 1998, has not been used broadly. Recently the Mandel’s test enjoyed an increase in popularity, possibly because non-linear data points are now more straightforward to plot using spreadsheets (linear model).

In this Analytical Methods paper, José M. Andrade and María P. Gómez-Carracedo at the University of A Coruna examined the validity of the definition of the test provided by IUPAC. They compared this approach to Mandel’s original definition, presenting ten different scenarios from simulated data. These simulations vary by number of data points and magnitude of the variances of the linear (IUPAC) or non-linear (Mandel’s) models. Surprisingly, the authors concluded that the 1998 IUPAC interpretation of this test does not strictly adhere to the definition published by Mandel, and is only valid within certain key limitations. The authors provide useful recommendations to analytical chemists intending to use Mandel’s test in their calibration calculations.

Notes on the use of Mandel’s test to check for nonlinearity in laboratory calibrations
J. M. Andrade and M. P. Gómez-Carracedo
Anal. Methods, 2013, Advance Article
DOI: 10.1039/C2AY26400E

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