In-situ precise isotopic analysis of tungsten using laser ablation multi-collector inductively coupled plasma mass spectrometry (LA-MC-ICP-MS) with time resolved data acquisition

摘要: Measurements of 182W/183W, 184W/183W and 186W/183W ratios in solid geological samples have been carried out using laser ablation multi-collector inductively coupled plasma mass spectrometry (LA-MC-ICP-MS). A time resolved analysis (TRA) data acquisition technique was used to minimise integration losses transient signals also the risk lowering precision accuracy measurements due low signal intensity data. The resulting precisions were about 0.015%, 0.031% 0.039% (2σ) when an optimised area expansion stabiliser used. These values are only 3-times worse than those achieved by conventional solution nebulisation measurements. However, total amount W for isotopic 20 ng, which is much less (0.1–0.01) typical required method. Measured a pure filament wolframite showed excellent agreement with from chemical reagents: 182W/183W = 1.85147 ± 0.00022, 2.14169 0.00022 1.98764 0.00021 (2σ) normalised 186W/184W ≡ 0.92805, obtained nebulisation. internal LA-MC-ICP-MS sufficient detect natural variations ratio originating radiogenic contributions 182Hf (typically 0.04– 0.2%).