Element concentration and isotope composition of solid and liquid are determined by mass spectrometry with isotope-dilution techniques.
Besides major elements, quantity of elements in planetary materials is limited such for one in a billion (1 ng/g). To estimate concentration and isotope composition of a element, we need to collect elements until we have enough. For example, we have to collect Pb by 10 ng. When concentration of Pb in a rock is small such for 1 ng/g, at least we need a rock of 10 g.
In the Chemistry Clean Laboratory, we dissolve the rock, extract elements, and do mass spectrometry. On dissolution of a rock, addition of acid and evaporation of aqueous media were repeated. We need to minimize unexpected elements coming from reagent and environment. We created a dedicated room with special air circulation named as the Ultimate Clean Room that stays on the upper stream of air flow.
Mass spectrometry is the most sensitive approach to determine both element concentration and isotope composition. The collected elements would be loaded into mass spectrometer in a form of solid or liquid and number of ionized atoms delivered to detector was determined. Since ion signal fluctuates in mass spectrometry, to cancel out, we intentionally mix elements with isotope-ratio known to the sample. This technique is called isotope dilution and at least we have to know quantities of sample and mixed elements.
The isotopically-doped solid and liquid were analyzed by appropriate mass spectrometers with the adequate method on the downstream of the ultimate clean room. To be able to analyze 52 elements and 5 isotope-system, the clean room keep expanding and will be, until we determine all elements and all isotopes. No problem since samples and disciplines are taken over to the next generations.
*Note: Please click and individual room from the map below to access the room and check the technical utilities and analytical capabilities of them.