The CAMECA NanoSIMS 50L is a secondary ion mass spectrometer. Primary ions (caesium or oxygen) bombard a solid sample. Secondary ions are emitted and separated according to their mass. The most abundant and usually analysed secondary ions are monoatomic species (12C-, 13C-, 16O-). An exception are nitrogen isotopes which are emitted as cluster (CN-) because the stability of a single nitrogen ion (N-) is low and this species is not received in high amounts.
In theory, nearly all elements can be analysed. However, in the practical analysis the signal intensity needs to be sufficient. Signal intensities of ions depend on the concentration of the atom in the sample, the matrix-dependent ionisation probability and the transmission of the ions in the NanoSIMS. Above this, it needs to be validated, that the right signal is analysed without interference by other signals. To achieve this, the NanoSIMS is a sector field instrument with the potential to resolve signals of the same mass like 13C und 12C1H. Thus, isotopic analyses in the per mill range are possible.
Due to its coaxial lens optics a lateral resolution reaching down to 50 nanometres is possible.Seven masses can be analysed at the same time. Thus, the parallel detection of several isotopes for e.g. single microorganisms is possible. The typical range for picture analysis is from 5*5 µm to 50*50 µm with e.g. 256*256 pixels.
For more detailed background of secondary ion mass spectrometry please see