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Sample Vaporisation A powerful
Nd-YAG laser is focused onto the sample to vaporise a
small area. The ablated material is quantitatively
transported, in a stream of argon, from the ablation cell
to the ICP torch for analysis.
This sampling method offers high sensitivity and,
because of the lack of sample pretreatment or
dissolution, there is little risk of sample
contamination. Direct analysis of the sample vapour also
minimises the amount of water introduced into the plasma
which can reduce the oxide interfaces by a factor of 100
compared to solution nebulisation.
Laser Aim And Control
After loading the sample into the ablation cell it is
viewed using a closed circuit TV (CCTV) camera and
monitor. All aspects of laser focus (X,Y& Z), laser
firing and sample position are under computer control
through the PC used to run the SOLA. This enables the
user to quickly and easily select the area of the sample
to be measured. A single laser pulse can be used to
analyse a very small area of the sample. Depth profiling
of element concentrations can be obtained by continuing
to fire the laser at the same sample area without moving
the sample stage. It is also possible, using the
computer, to move the sample whilst firing repetitive
laser pulses, to analyse selected sample areas.
This analysis method provides elemental concentrations
in the area selected or on the spatial distribution of
elements measured. To provide the maximum flexibility the
laser beam focus can be adjusted from 20 microns to
greater than 200 microns.
Laboratory Safety
The model 266 Laser Ablation System has been
specifically designed to meet current International
safety requirements. Careful and rigorous design of the
unit guarantees that the operator cannot be exposed to
laser light by improper operation.
Interlocks are present at every level to provide an exceptional degree of safety. The model 266 can easily be
fitted to any SOLA and operated in any open laboratory.
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