History of TOFMS - A Kore perspective
Early Laser Microprobe MS for solids
The Bendix Corporation marketed the first commercial time-of-flight mass analyser, based on the design of the Wiley MacLaren instrument, in the late 1950's. However TOFMS suffered from poor resolution and did not begin to become a viable mass spectrometry technique until the arrival of affordable fast timing electronics in the 1970's. Kore can claim to be involved in this renaissance of time-of-flight mass spectrometry. In 1978 one of Kore's founders designed the world's first laser microprobe, with a "Mamyrin" reflectron time-of- flight mass analyser, for bulk (solid) sample analysis. This instrument was initially designed for hydrogen embrittlement studies at weld boundaries and subsequent instruments were applied to materials analysis and microelectronics applications.
The emphasis on inorganic analysis was largely because ion production efficiency started to substantially decrease at masses around 5-10kDa, depending upon whether special sample preparation, such as a silver substrate, was made. However in 1987, Michael Karas and Franz Hillenkamp, at the University of Muenster, successfully demonstrated that mixing a low concentration of the sample analyte within a small organic molecule matrix, (which had a strong absorbance at the laser wavelength), broke through the mass limitation. The matrix also allowed for the laser analysis area to be refreshed between each pulse, greatly enhancing shot-to-shot reproducibility. This was the foundation of Matrix-Assisted Laser Desorption Ionisation (MALDI) and the subsequent explosive growth in such instrumentation in Biosciences applications. Unfortunately for the Germans it was the earlier use of a silver particle matrix to demonstrate MALDI that resulted in Koichi Tanaka, of Shimadzu Japan, receiving a part share with John Fenn of the 2002 Noble prize for chemistry.
Meanwhile Kore personnel were getting involved in the other, albeit less explosive growth area for solid sample TOFMS-Secondary Ion Mass Spectrometetry. Alfred Benninghoven at the University of Muenster, who was one of the pioneers in this field, completed a TOF-SIMS in 1979 using a Poshenreider mass analyser. His group subsequently replaced the Poshenreider mass analyser with a reflectron because of its smaller size and to increase the mass resolution.
In the 1980's Kore personnel were involved in developing and selling numerous surface analysis instruments, based around time-of-flight secondary ion mass spectrometer (SIMS) technology. An example of this type of large surface analysis instrument designed by Kore is the BioTOF-SIMS instrument. This came about through the vision of Prof. Nick Winograd at Pennsylvania State University. He wanted to have a system that could perform very high resolution spatial imaging SIMS on fully hydrated biological specimens. He realised that acceptable signal to noise might only be possible with a high efficiency post-sputtering ionisation scheme and also that a high performance cold stage and cold sample preparation systems would be required.
However Kore was not only involved in these large and relatively expensive SIMS instruments. In 1995 the UK Department of Trade and Industry (DTI) granted Kore an award to develop a novel table-top SIMS. This was an inexpensive solid sample surface contamination analyser for product research and development, quality control and fault diagnosis.
Prototype portable MS
A completely different application of Kore's time-of-flight mass spectrometer technology resulted in the world's first truly portable TOFMS. This development program started in 1993 when the UK DTI awarded Kore a SMART award for a feasibility study and then further funding to produce a production prototype portable pollution monitor. To date Kore has sold numerous portable mass spectrometers to research groups throughout the world, for use in diverse applications ranging from the health and environmental field to homeland security.
Increasingly in the 21st century Kore has focused on its Design-for-Research business in which Mass Spectrometry Systems are supplied to researchers that require a high performance, flexible system, designed to allow them to fully explore their particular applications. For example in 2002 we started designing Proton Transfer Reaction TOF (PTR-TOF) systems for the Detection of Ultra-Low Concentrations of Compounds in Air. The ability of PTR- TOF to detect very low levels of a variety of organic species in complex matrices makes it an attractive technique for other areas such as medicine and food technology. In 2005 we have received an order for a new PTR/APCI TOF-MS instrument designed to allow researchers at Nottingham University's Division of Food Science to monitor the appearance of flavour molecules with elapsed time on the breath of a person who is sampling a food product.
Other examples of Design-for-Research Systems that we have supplied recently include a compact TOFMS system for time-resolved kinetic studies of gas phase reactions and a research TOF-MS instrument which will be used to characterise the masses and distribution of metal clusters.
Over the years Kore personnel can claim to have been involved in most facets of the development of time-of-flight mass spectrometry and this we would claim has made Kore a centre of excellence in time-of-flight mass spectrometer technology.
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Last updated: Wednesday, July 25, 2007, 15:08
© Kore Technology Limited 2005