Capabilities of Automated LA-ICP-TOFMS Imaging of Geological Samples
Mapping the distribution of elements in minerals by laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) is of growing interest in earth sciences. The resulting images can reveal important petrological parameters, e.g. chemical composition of the source melt, pressure and temperature of crystallization, and diffusion behavior of different elements within the mineral. In combination with fast-washout laser ablation systems and time-of-flight mass spectrometers (TOFMS), such as TOFWERK’s icpTOF instruments, elemental imaging can be done very rapidly (i.e. 100 pixels per second, or higher).
Neff et al. describe LA-ICP-TOFMS imaging using a new image control and processing software – TEMAimaging – which is available under an open-source license ( https://github.com/ethz-tema/TEMAimaging ). In addition to performing spot-resolved imaging whereby one laser shot produces one multi-element pixel in the image, they describe a hole-drilling image approach whereby each pixel contains the signal from multiple laser shots. This hole-drilling approach greatly improves the sensitivity of the method. The authors demonstrate the applicability of LA-ICP-TOFMS imaging on two natural rock samples (i.e., an ilvaite-hedenbergite assemblage, and an ilvaite-quartz assemblage). Quantification of element mass fractions in the samples was performed for each pixel based on 100 % mass normalization.