Informing Spectroscopists for Over 40 Years

Articles

Fourier transform infrared spectroscopic imaging of live cells

Jennifer A. Dougan, Sergei G. Kazarian

There are a number of approaches, and by combining FT-IR imaging methodology with microfluidics devices, the opportunity to study live cells by FT-IR imaging in controlled environments is now possible.

Article  |  Issue 25/5 (2013)

The last furlong (1). Data compression

A.M.C. Davies

Tony (A.M.C.) Davies starts a review of the chemometric ideas that have most excited him over the last 30 years. In this column, he looks at the use of Fourier transformation for data compression. FT can also provide the side benefit of reducing high-frequency noise.

Tony Davies Column  |  Issue 25/2 (2013)

Qualitative and quantitative assessment of acetylated wood using infrared spectroscopic methods and multivariate data analysis

Manfred Schwanninger, Barbara Stefke, Barbara Hinterstoisser

Chemical modification of wood by methods such as acetylation is required to improve characteristics such as photosensitivity and combustibility, and to provide harmonisation of wood properties in order to avoid swelling and shrinking and to improve biodegradability. The authors describe the use of mid and near infrared spectroscopies to monitor chemical changes due to acetylation is described. 

Article  |  Issue 25/2 (2013)

Single particle characterisation in biologics: from mid-infrared micro-spectroscopy and mapping to spectral imaging

Patrick Garidel

The presence of “particles” in protein pharmaceuticals (biologics) can cause severe, unwanted effects in the drug. The article describes the use of mid-infrared micro-spectroscopy for the investigation and chemical characterisation of single particles in these biologics.

Article  |  Issue 25/1 (2013)

Variable selection for regression analysis: an up-date on an old problem

A.M.C. Davies, Tom Fearn

Tony (A.M.C.) Davies and Tom Fearn describe an enhancement of the popular partial least squares (PLS) technique, powered partial least squares (PPLS),  that has shown significantly better results.

Tony Davies Column  |  Issue 24/6 (2012)

Surface-enhanced infrared spectroscopy

Frank Neubrech , Annemarie Pucci

In principle, electromagnetic SEIRS should be as strong as electromagnetic surface-enhanced Raman scattering (SERS) but, in SEIRS, disturbing fluorescence is absent. In order to get maximum IR vibrational signal enhancement for sensing of rare molecules, strong resonant scattering of plasmonic objects is recommended.

Article  |  Issue 24/5 (2012)

What IS and what is NOT chemometrics

A.M.C. Davies

Tony Davies makes sure we understand “What IS and what is NOT chemometrics” and why it matters.

Tony Davies Column  |  Issue 24/4 (2012)

Measuring brain activity using functional near infrared spectroscopy: a short review

Felix Scholkmann, Martin Wolf

“Measuring brain activity using functional near infrared spectroscopy: a short review” by Felix Scholkmann and Martin Wolf looks at the various methods for performing fNIRS and some applications that demonstrate why this non-invasive, safely applicable, portable and cost-effective method is now an integral part of the techniques used in neuroscience.

Article  |  Issue 24/4 (2012)

Infrared spectroscopy of nucleoprotein complexes

A. Roque, I. Ponte, P. Suau

A. Roque, I. Ponte and P. Suau look at “Infrared spectroscopy of nucleoprotein complexes”. The advantages of IR spectroscopy have allowed them to determine the structure of linker histones and ­protamines as they interact with DNA. Linker histones are involved with the condensation of the thick chromatin fibre and are believed to have a regulatory role in transcription through the modulation of chromatin higher order structure.

Article  |  Issue 24/4 (2012)

Reverse engineering of polymeric multilayers using AFM-based nanoscale IR spectroscopy and thermal analysis

Tom Eby, Usha Gundusharma, Michael Lo, Khoren Sahagian, Curtis Marcott, Kevin Kjoller

It is possible to obtain both infrared spectra and thermal analysis data of individual layers in a cross-sectioned multilayer film. Since both techniques are AFM-based, the topographical features can be readily linked to the spectroscopic and thermal data at a much higher spatial resolution than previously achievable.

Article  |  Issue 24/3 (2012)

Examining diffuse reflection and transmission spectra more thoroughly: Part 2. Sample temperature and sample composition

Karl H. Norris, A.M.C. Davies

The Tony Davies Column once again contains a contribution from Karl Norris, who is widely regarded as the “father of NIR spectroscopy”. Karl continues to produce innovative ideas about the field and this article is no different. Building on the previous article concerning fourth derivatives, Karl has investigated the effect of varying gap sizes with some remarkable results.

Tony Davies Column  |  Issue 24/2 (2012)

ATR/FT-IR spectroscopy for the characterisation of magnetic tape materials

Elena Gómez-Sánchez, Simon Kunz, Stefan Simon

Do you remember magnetic tape-to-tape recorders and players? In any case, I am sure you will be interested in this article looking at the use of FT-IR spectroscopy to help the conservation of tapes in the collection of the National Museums Berlin. In “ATR/FT-IR spectroscopy for the characterisation of magnetic tape materials”, Elena Gómez-Sánchez, Simon Kunz and Stefan Simon describe how by investigating the state of the base layer of the tape, conservation efforts can be prioritised to those tapes in most immediate danger.

Article  |  Issue 24/1 (2012)

Examining diffuse reflection and transmission spectra more thoroughly: Part 1. Instrument noise

Karl H. Norris, A.M.C. Davies

This Tony Davies Column is contributed by Karl Norris, known to many as “The father of near infrared spectroscopy”. He introduces his calculation method for fourth derivatives and shows how it can be used to extract instrument noise.

Tony Davies Column  |  Issue 23/6 (2011)

New broadband high-resolution ozone absorption cross-sections

Anna Serdyuchenko, Victor Gorshelev, Mark Weber, John P. Burrows

With the threat of climate change, understanding the workings of our atmosphere is of crucial importance. Ozone is the most important trace gas in the stratosphere and troposphere and it is monitored by both satellite-borne and ground-based instruments. Accurate knowledge of ozone absorption cross-sections is vital for this work and described in this article.

Article  |  Issue 23/6 (2011)

The African crested rat's poisonous hairs studied by attenuated total reflection infrared spectroscopy

Maxime Boulet-Audet, Chris Holland

The African crested rat chews poisonous bark and then applies its saliva to specialised hairs which provide a most effective protection. Maxime Boulet-Audet and Chris Holland describe this and the use of infrared spectroscopy to learn more about this unusual animal. The new knowledge may even lead to new treatments for human cardiac conditions.

Article  |  Issue 23/6 (2011)

Evaluation of sensory and composition properties in young tea shoots and their estimation by near infrared spectroscopy and partial least squares techniques

Zheng-Zhu Zhang, Sheng-Peng Wang, Xiao-Chun Wan, Shou-He Yan

Tea is harvested from the bud, the first leaf and the first three leaves up to a maximum of four leaves. Quality decreases from the bud down as the parts become older. This study looks at the use of NIR spectroscopy to determine optimal production using the harvested material.

Article  |  Issue 23/4 (2011)

Always look at the spectrum: Part 2. 3-D Normalisation

A.M.C. Davies

Tony (A.M.C.) Davies is again telling us to “Always look at the spectrum”. This time he uses an example from the development of a NIR spectrometer to demonstrate that one doesn’t really know what’s going on until one has “looked at the spectrum”.

Tony Davies Column  |  Issue 23/4 (2011)

Protein concentration prediction in cell cultures: the next stage in near infrared bioprocess analysis

Todd Strother

This article shows that NIR spectroscopy offers the potential for bioprocess manufacturing companies to limit the variability in the biological production process, thereby increasing the yield and reducing the number of errors.

Article  |  Issue 23/3 (2011)

Near infrared spectroscopy in bioreactor performance monitoring

J. Reed, A.N. Davies

Anaerobic digestion is a good solution to the joint problems of dealing with organic waste and producing “clean” energy. However, running the digesters at optimum performace is a complex business. NIR spectroscopy offers a solution to monitor a number of analytes within the reactor and in real time.

Tony Davies Column  |  Issue 23/3 (2011)

Always look at the spectrum: Part 1. NIR noise spectra

A.M.C. Davies

Tony (A.M.C.) Davies stresses the importance of always looking at the spectrum, even if you [think you] know there’s nothing to learn. He relates his experience with noise in NIR spectra and what he has learnt from it. He would like us all to examine spectra for abnormality before relying on automated methods.

Tony Davies Column  |  Issue 23/2 (2011)

Pages