Apatites are currently of major interest in a number of fields: biomaterials, solid oxide fuel cells, catalysis, environmental remediation to name a few. Hydroxyapatite - Ca10(PO4)6(OH)2 - and its Ba and Sr analogues can accommodate a range of transition metals not, as might be imagined, on the cation sites, but instead the doping is reported to occur on the hydroxyl sites, leading to a TM-oxy-hydroxyapatite (M-O-OH). Comparisons in the literature are difficult as there it is highly contradictory. In addition, with X-rays the mechanisms of the substitution are very difficult, if not impossible, to follow, and hence we wish to study the (M-O-OH) groups within the structure as a function of:(a) composition (b) annealing temperature(c) route of synthesiswith the ultimate aim of optimising the route of synthesis and metal incorporation without losing all OH groups.