chemical analysis

IR research has been carried out in the James Hutton Institute for over 50 years including much of the pioneering work on IR of minerals. The Infrared (IR) Section at the James Hutton Institute has both FTIR (Fourier Transform Infrared) and NIR (Near Infrared) capabilities. Total reflectice x-ray fluorescence (TXRF) is used in the area of environmental (soil solutions, soil suspensions, fresh water, wastewater, sewage), food and drink, medical (blood, serum, urine), pharmaceutical and forensic analysis.

Principal contacts for chemical analysis:

Jean Robertson – FTIR and NIR

Charles Shand – TXRF

Instrumentation

FTIR

Photograph of the Bruker Vertex 70 FTIR

The section has a Bruker Vertex 70 FTIR spectrometer with the facility to record spectra in both the mid infrared (4000 – 400 cm-1) and the far infrared (600-50 cm-1). A DurasamplIR accessory and a Harrick ATR sampling accessory allow DATR spectra to be recorded for both these spectral regions. In addition the FTIR spectrometer has an automated Bruker Hyperion 2000 FTIR microscope attached to it. Software is OPUS (version 6)

NIR

The NIRS is a FOSS NIRS 5000 with a range from 100 -2500nm. The sampling attachment is a Transport Module into which of a range of Sample cells, most commonly Quarter Cups or Ring Cups, can be slotted vertically. The software is ISIscan and WINISI III.

Use of Techniques

FTIR

IR research has been carried out in the James Hutton Institute for over 50 years including much of the pioneering work on IR of minerals. Spectra can be recorded on the FTIR for a large range of sample types. The infrared spectrum gives a chemical overview of the sample composition and both organic and inorganic substances present in a sample contribute to the spectrum. IR analysis involves interpretation of the spectra to determine what chemicals or chemical groups are present.

Currently within the James Hutton Institute research projects, IR analysis is being undertaken of many naturally occurring materials including: soils; vegetation; fungi; particulate matter from streams; minerals, including clay minerals; root exudates and animal faeces. Typically, work can include such things as assessing the degree of decomposition of peat samples, looking at how the nature of chemicals present in fungi alters with the growth medium or examining the degree of crystallinity of a mineral sample.

In addition to the internal research work, IR analysis is carried out for commercial customers. This work concentrates more on material characterisation and identification. It can be applied to a vast range of sample types and includes analysis of such things as sludge blocking oil pipes, failed “O” rings and plastic material found in foodstuff.

NIR

NIR analysis was introduced to the IR section much more recently than the FTIR. Spectra recorded on the NIRS are used in conjunction with wet chemistry analysis of the samples to build calibration models. These calibration equations allow the subsequent prediction of the relevant constituents in unknown samples. This is a powerful, quick and non-destructive technique in which several parameters can be predicted from a single spectrum. Currently in the James Hutton Institute we are developing calibrations for soil, vegetation of various types and deer faeces for the use in research projects.

Contact: Jean Robertson (Tel: 01224 395119) for all FTIR and NIR.

Total reflection x-ray fluorescence (TXRF) 

Photograph of the TXRF

The S2 Picofox from Bruker is a bench top spectrometer for fast quantitative and semi quantitative multi-element microanalysis of liquids, suspensions, solids and contaminants using the principle of total reflection X-ray fluorescence spectroscopy. With detection limits in the µg/kg to mg/kg range it is applicable for trace elements analysis.  The ability to analyze very small samples (10 µl) directly with minimal sample preparation makes matrix effects negligible.Typical applications are in the area of environmental (soil solutions, soil suspensions, fresh water, wastewater, sewage), food and drink, medical (blood, serum, urine), pharmaceutical and forensic analysis.

Hand held x-ray fluorescence (XRF)Photograph of hand held x-ray fluorescence (XRF) 

The S1 TurboSD from Bruker is a fully field portable analyser with integrated Personal Digital Assistant (PDA) computer. In the instrument, X-rays are generated from a tube source and not from a radioactive source. The fluorcescence is detected using a Peltier-cooled silicon drift detector. When used in the vertical stand it can also be used as a bench top tool. It uses x-ray fluorescence spectrometry to analyse major and trace elements. It can be used for the screening for example of contaminated hot spots and the characterisation of rocks, ores and soils. For mapping purposes the unit can be linked with GPS technology.

Microplate Spectrophotometer

The SPECTRAmaxTM 190 Microplate spectrometer from Molecular Devices measures the optical density of samples in a microplate. Typical applications include endpoint assays and kinetic measurements.

Contacts:  Charles ShandRenate Wendler