Analytical Methods Blog

Nowadays we all know the health risks posed by asbestos, and the great lengths taken to detect it and eliminate it from our environment. At one point, however, asbestos was used in everything from insulation material and flooring material to the brake linings used in cars, meaning there is plenty of it still out there.

Current methods of asbestos analysis are geared towards looking at building materials, but are not sensitive enough to detect the substance in soil. But recent work by a team of US scientists could solve this problem, boosting the sensitivity of the technique 100-fold.

To read the full article please visit Chemistry World.

Evaluation of a fluidized bed asbestos segregator preparation method for the analysis of low-levels of asbestos in soil and other solid media
J. Januch, W. Brattin, L. Woodbury and D. Berry
Anal. Methods, 2013, Advance Article
DOI: 10.1039/C3AY26254E

When it comes to brandy, analysis is an important part of the production process. It’s usually carried out by a panel sense experts, but now a team of Spanish scientists is set to replace the human palette with an electronic tongue that classifies brandy according to taste, and can even discriminate between aging methods.

An electronic tongue is an analytical system that mimics the sense of taste using an array of sensors and advanced signal-processing methods. Where classical analytical chemistry involves the identification of individual chemical species, an electronic tongue creates a fingerprint using multiple signals from its sensor array. This is useful for looking at alcoholic beverages, in which the species responsible for specific tastes are often unknown.

To read the full article please visit Chemistry World.

Application of an electronic tongue towards the analysis of brandies
Xavier Cetó ,  Matias Llobet ,  Joan Marco and Manel del Valle
Anal. Methods, 2013,5, 1120-1129
DOI: 10.1039/C2AY26066B

A technique to measure how effective chemotherapy is by studying the physical changes that occur in human cells has been developed by US scientists. The method combines atomic force microscopy and Raman spectroscopy to detect biomechanical and biochemical changes in the cells.

The effectiveness of chemotherapy is usually determined by measuring levels of cytokines (cell-signalling proteins) and chemokines (proteins secreted by cells), as well as cell viability, but these traditional methods cannot provide data on single cells, nor do they have the ability to image cells in vitro.

Atomic force microscopy images of (a) cancerous human lung cells and (b) benign human lung cells

To read the full article please visit Chemistry World.

Non-invasive detection of biomechanical and biochemical responses of human lung cells to short time chemotherapy exposure using AFM and Confocal Raman Spectroscopy
Lifu Xiao ,  Mingjie Tang ,  Qifei Li and Anhong Zhou
Anal. Methods, 2012, Accepted Manuscript
DOI: 10.1039/C2AY25951F

Scientists in Brazil have shown that luminescent lanthanide tags can be added to ammunition to enable visual identification of gunshot residue at crime scenes, and even on a shooter’s hands, using an ultraviolet lamp.

Scanning electron microscopy-energy dispersive spectroscopy analysis is currently used to identify some types of gunshot residue, but environmental and occupational contamination can give false negatives. The method is also time-consuming and limited by the need to obtain adequate sample quantities. Another problem is that lead-free ammunition is now coming into use to avoid lead pollution and its resulting impact on human health. (The blood level of lead in shooting instructors, for example, is near the limit set out by the National Institute for Occupational Safety and Health of 60µg lead per 100g blood.) But, this ammunition cannot be unequivocally identified, as the techniques used rely on identifying lead as a characteristic compound in gunshot residue.

Luminescent lanthanide-doped ZnAl2O4 added to lead-free ammunition to provide a way to identify lead-free gunshot residue (GSR)

 To read the full article please vist Chemistry World.

ZnAl2O4-based luminescent marker for gunshot residue identification and ammunition traceability
M. A. Melo Lucena ,  G. F. de Sá ,  M. O. Rodrigues ,  S. Alves ,  M. Talhavini and I. T. Weber
Anal. Methods, 2013, Advance Article
DOI: 10.1039/C2AY25535A

An on-demand system to print artificial fingerprints has been developed by US scientists. The fingerprints could be used to ensure that detection equipment for explosives and narcotics, such as those used in airports and federal prisons, are working as expected.

Jessica Staymates and her team at the National Institute of Standards and Technology, Gaithersburg, incorporated the oily substance found in fingerprints – sebum – into explosive test materials to provide a realistic challenge for trace detection technologies. ‘When someone handles explosive or narcotics materials, they inevitably contaminate themselves, their clothing and belongings with micrometre-sized particles of the material,’ explains Staymates. ‘It is generally believed that these trace residues are commonly spread via fingerprints.’

White light (left) and polarised light micrographs of sebum-heptane-RDX-polyisobutylene mix printed in a fingerprint-like array

 To read the full article please visit Chemistry World.

Evaluation of a drop-on-demand micro-dispensing system for development of artificial fingerprints
Jessica L. Staymates, Matthew E. Staymates and Greg Gillen
Anal. Methods, 2013, Advance Article
DOI: 10.1039/C2AY26167G

UK scientists have shown that plants can be used to detect nerve agents.

Nerve agents such as the acetylcholinesterase inhibitor, VX (O-ethyl S-[2-(diisopropylamino)ethyl] methylphosphonothioate), are extremely toxic substances banned by the Chemical Weapons Convention. Unfortunately, they can still be used to terrifying effect in the wrong hands, with one example being the sarin attacks in the Tokyo Metro in 1995.

The V nerve agents, of which VX is the most famous, was discovered by accident during work on organophosphate pesticides

To read the full article please visit Chemistry World

Detection of the organophosphorus nerve agent VX and its hydrolysis products in white mustard plants grown in contaminated soil
Matthew R. Gravett,  Farrha B. Hopkins,  Marcus J. Main,  Adam J. Self,  Christopher M. Timperley,  Andrew J. Webb and Matthew J. Baker
Anal. Methods, 2012, Advance Article
DOI: 10.1039/C2AY25883H