Department of Human Evolution
Max Planck Institute for Evolutionary Anthropology
Deutscher Platz 6
phone: +49 (341) 3550 - 350
fax: +49 (0341) 3550 - 399
The analytical core of this laboratory is a ThermoFinnigan Neptune Multi collector (MC) inductively coupled plasma (ICP) mass spectrometer (MS). Multi collector means that the mass spectrometer has an array of detectors, mainly Faraday cups, to simultaneously measure ion beams of different isotopes. Ionisation of a sample is achieved by injecting the sample into a so-called plasma, which is generated on an Ar gas stream within a so-called torch.
A Sample - usually in a weak acid solution - is nebulised into a spray chamber, where it is mixed with an Ar stream and then injected into the plasma ('wet plasma condition'). We also have a Cetac Aridus II which removes the vapour from the Ar - sample mixture before it is injected into the plasma ('dry plasma condition'). We furthermore have a Cetac Quick Wash system for the Aridus II spray chamber and a Cetac ASX 112 autosampler system.
We have installed the Neptune 'plus' interface pump for increased transmission efficiency. Our Neptune has an array of nine Faraday cups. Eight Faraday cups are movable and the centre cup is fixed. The centre ion beam can be measured with the centre Faraday cup or - for low ion intensity beams - deflected to a secondary electron multiplier (SEM) ion counting detector which is located behind an energy filter (RPQ). We also have additional miniature channeltron ion counters attached to Faraday cups allowing static collection of low level ion beams, which is important for laser ablation analyses.
Main applications in our laboratory are currently U-series isotopes, Zn isotopes, Cu isotopes or Sr isotopes. We also have a Photon-machines laser ablation system with a HelEx laser cell for in situ laser ablation isotope measurements, e.g. for Sr isotope measurements or U-Th age estimates.