Fig. 2. Normalized X-ray absorption spectra of the Ca orthophosphate standards (ACP: amorphous calcium phosphate; ß-TCP: beta tricalcium phosphate; DCPA: dicalcium phosphate anhydrous; DCPD: dicalcium phosphate dihydrate; HAp: hydroxylapatite; OCP: octacalcium phosphate) (a: whiteline, b: shoulder, c: distinct peak, d: oxygen oscillation).