Raman spectroscopy was used for the characterization of the precipitated phosphate minerals. 
Raman spectroscopy
Phosphate mineral formation on the supported dipalmitoylphosphatidylcholine (DPPC) layers.Dipalmitoylphosphatidylcholine (DPPC) mono- and bilayers supported on mica surface were soaked for two weeks in a simulated body fluid (SBF) with ion concentrations nearly equal to those of human blood plasma. 
SBF
Two solutions were investigated: with and without Tris.  In the solution without Tris temperature increase gives more mineral deposits.  It is probably the hydrogen interactions between phosphate groups of the phospholipid and hydroxyl groups from Tris that lower exposure of the phosphate group to interact with calcium ions.
Tris