The MC-ICP-MS (Multiple Collector - Inductively Coupled Plasma -Mass Spectrometry) is installed since August 2007 in the  Marine Geosciences Department at IFREMER. The instrument ( Neptune, Thermo Fisher Scientific) was founded by IFREMER, EU-FEDER, the Region of Britany and the Department of Finistère. The mass spectrometer is dedicated to high resolution isotope ratio measurements (measurements uncertainties ~ 0.005%).

After chemical separation of the element under study, the samples are introduced in liquid phase by a pneumatic nebulizer in a spray chamber. The produced aerosol is then injected into the plasma (~ 8000°C) to be desolvated, atomised and ionised. The ions are extracted into the mass spectrometer and dispersed according their m/z ratio by a magnetic sector. The isotopes are finally collected simultaneously by a collector array. The Neptune at IFREMER is equipped with 9 Faraday Cups (8 mobiles), 1axial ion counter featured with an RPQ (Retarding Potential Quad) and 2 mini ion counters (MICs). It is possible to work at 3 fixed resolutions (LR: Low Resolution: 400; MR: Medium Resolution: 4000; HR: High Resolution: 10000).