“…18,19 However, all these techniques require the crystal sample to be digested, and, thus, they only provide information on the average content of elements in the whole crystal, while ignoring information on the spatial distribution. To date, X-ray fluorescence spectroscopy (XRF), [20][21][22] mass spectrometry (GD-MS), 23,24 secondary ion mass spectrometry (SIMS) 25,26 and electron probe microanalysis (EPMA) 27 have been the most suitable methods for in situ and elemental distribution analysis of solid materials. However, these methods have both advantages and disadvantages when applied to solid-sate analysis.…”