A solution to the elemental characterisation of materials

In an outcome recalling one of Australia's greatest scientific achievements, researchers from the CRC for Clean Power from Lignite (CRC CPL) have designed and commercialised a revolutionary instrument. The 'Spectrolaser' is a powerful new tool for analysing the atomic elements in virtually any material, quickly and cheaply.

The Spectrolaser's commercial development through high-tech company Laser Analysis Technologies harks back to the success of atomic absorption spectroscopy, discovered in Australia in 1952. That analysis technique is used today in hospitals and laboratories throughout the world.

The Spectrolaser is a high-tech offspring of the coal industry. The idea grew out of the CRC's research into coal gasification and the instrument was initially designed to perform rapid analyses of coal quality, to help power stations operate more efficiently.

Coal varies in moisture, organic components and trace elements. Some coals burn better than others, some cause greater corrosion of furnaces, others deposit more ash and char. If operators understand the composition of the coal before it is fed into a furnace, then combustion conditions can be tweaked to improve burning efficiency and reduce fouling.

However, the Spectrolaser can also be used to analyse minerals, building materials, metals and alloys, pharmaceuticals, manufactured products and to carry out environmental monitoring.

"Like atomic absorption, laser spectrometry has an enormous range of potential uses in industry, healthcare and the environment," explains CRC CPL chief executive Dr Jackson.

"Another great advantage is that the instrument can be built using off-the-shelf components and is therefore relatively low cost," he adds.

"Most of the value has been added in the smart software that operates the system, and in creating a library of characteristic emission signatures to automate element identification."

The Spectrolaser is an elemental analysis instrument based on a technique called LIBS (laser induced breakdown spectroscopy). It incorporates a high-power laser that induces a bright spark (or plasma) at the surface of the material being analysed, the light from which is subsequently analysed by a unique spectrometer and detection system. The elemental fluorescence is directly related to the concentration of the element in the material being analysed.

The Spectrolaser enables the rapid determination of all detectable elements simultaneously. In brief, the instrument incorporates a unique parallel processing design which utilises multiple spectrographs and CCD detectors. A continuous coverage of wavelengths from 180 nm to more than 800 nm is maintained at the resolution required to observe the elemental fluorescence with minimal interference. The acquisition circuitry allows the spectral range from each spectrograph to be recorded in a single laser pulse. The wavelength calibration remains constant over long periods and the design is sufficiently rugged to be used reliably in field applications.

A large range of additional elements is detectable, including most metals and important material components such as N, O, C and H. Detection limits vary depending on the particular element and the sample matrix. Long-term comparison studies show excellent agreement between the analysis obtained when using the Spectrolaser and elemental analysis obtained by traditional acid extraction and analysis by AAS (atomic absorption spectroscopy).

To find the right partner to get to market, the CRC team conducted a careful search and identified Automated Fusion Technology Pty Ltd (AFT), a Melbourne-based firm with a 10-year track record for quality instrumentation.

The intellectual property of the CRC in the Laser Plasma Spectrometer - including two patents, software source codes, circuit board designs, schematics, and available know-how - was exclusively licensed to the joint venture, Laser Analysis Technologies Pty Ltd in 2002.

Two years later, Automated Fusion Technology Pty Ltd merged with a number of other companies to form XRF Scientific Ltd, and LAT subsequently became part of the merged XRFS Group.

"The Spectrolaser continues a 50-year tradition in Australia as a discoverer, developer and exporter of precision scientific instrumentation.

"Today this industry earns almost a billion dollars a year from exports, and underpins the quality of a great many of our other export products and commodities.

"There is strong overseas interest in the Spectrolaser, and we are optimistic it will build on this great Australian tradition for making quality scientific instruments."

Dr Jackson says the research addresses National Research Priority number two - frontier technologies for building and transforming industry.