Laser ablation inductively coupled plasma mass spectrometry (LAICPMS)

About this technique

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LAICPMS is used to quantify trace elements in a sample. This involves focussing a high-energy, pulsed-UV laser onto the surface of the sample, releasing (or ablating) material that is then transported into the argon plasma where it is broken down into constituent atoms and ionised. It then passes into the mass spectrometer where the elements of interest are analysed. It can analyse individual spots or, in some instruments, the focussed laser beam can be rastered the across the sample so that intensity and spatial distribution of elements can be recorded. Post acquisition processing then allows an image of elemental intensity to be compiled.
Existing techniques used to investigate trace element distribution in mineral and biological samples include electron probe microanalysis, transmission electron microscopy, scanning electron microscopy, ion microprobe, proton microprobe, synchrotron X-ray fluorescence and X-ray diffraction analysis. These all have their benefits, but also their inherent limitations such as high detection limits (>0.1–1.0 wt%), very small analytical areas, complex sample preparation, and often prohibitively expensive instrumentation. Although its spatial resolution will never compare to electron and proton beam techniques, imaging with LAICPMS offers the benefits of superior detection limits (ppb) over a wide elemental range from ⁷Li to ²³⁸U and the capacity to analyse a wide variety of materials with minimal sample preparation.
The success of mapping with LAICPMS depends on very fast signal response from ablation to detection, along with fast washout times in the ablation cell. Although standard cells do not offer this feature, more advanced cells are available in some of our locations. Performance is being optimised on a wide variety of samples including, minerals, plant material, and other biological tissue.