Good morning! Yesterday I had to stop writing since I was called up due to a problem with our mass spectrometer: An inductively coupled plasma mass spectrometer (ICP-MS). It’s a small and useful mass spectrometer. Not the best but it’s what we have. Yesterday’s problem was a typical ‘ICP-problem’. Our PhD-student had problems in operating the instrument since it shut down after just a few minutes operation. I could help solving the problem and then it was ok. Work with the ICP-MS is one of my main activity fields and the lab is my responsibility. If I have the time I spend most of my time in there, developing techniques and finding out how to improve the analytical methods. It’s easy to get mountains of data out from these instruments but they both lie and tell the truth, continuously. Over the years my main work has been to try and find out what to believe and how to prevent the instrument to lie. The ‘lies’ are called polyatomic interferences and are clusters of ions formed in the cooler parts of the hot (7000 C) plasma in the instrument. A signal or data that we obtain from the instrument is made up of both the analyte we are interested in (for instance U-238) and the cluster ions. The lower concentrations of our analytes the more problematic are these cluster ions. To be able to analyse the very low concentrations require that we completely have control of the magnitude of cluster ions formed. This is what I do. But I do this for a purpose. My original interest was in using elements and radioactive isotopes as tracers for changing oxygen conditions in aquatic basins. Fjords, brown humic lakes and the Baltic Sea was my paradise for several years. From these environments I retrieved several sediment cores and tried methods to squeeze out the interstitial pore water, often getting some 2-10 ml from each cm slice of sediment. In these