All,

I am new to gated fluorescence. We are using multiple pulsed LED wavelengths from 295-395nm to gather data at each wavelength. Using a delay of ~0.5us and a gate of ~10us to acquire a spectrum. The targets are various fossils made of calcium phosphate and are permineralized with a variety of other things. We know from previous studies and the fact they fluoresce, that they have REE's in the bone.

We are getting spectra with lots of peaks but when we try to match them up to standard spectra using doped glass beads, the peaks are off by ~5+nm. It seems the research done on minerals with a structured lattice expects peak positions within +-1nm but there is literature out there that talks about peak shifts and splitting due to more amorphous substrates. I can't get a handle of how much shifting would be allowed for a proper ID. Any comments on this would be appreciated.

Thanks!

Tom Kaye