December 2018 – Improved in-situ Li isotope analysis of synthetic glass – Neptune XT

In-situ measurement of Li isotopic compositions by coupling laser ablation (LA) to MC-ICP-MS reduces sample preparation, but also allows spatial resolved analysis. As Li is only present in trace amounts (typically a few μg/g) in many geological materials, LA-MC-ICP-MS measurements are challenging due to the low measured intensity (1–20 mV) of 6Li.

The recent development of 1013 ohm amplifier technology at Thermo Fisher Scientific extends the operating range of Faraday cup detectors to cover such small ion intensities. Compared to the standard 1011 ohm amplifier, the signal-to-noise ratio of the 1013 ohm amplifier is improved by 4 to 5 fold. This is reflected in the precision achieved at low signal intensities. The 7Li/6Li analysis of synthetic glasses by LA-MC-ICP-MS demonstrates the improvements in accuracy and precision for low intensity ion beams afforded by 1013 ohm amplifiers.

 

Download the application note AN30440 from the Knowledge Base.