- DTA curves of samples mineralized with 27 kDA pAsp and 0, 0.5,1, 2, 5, or 25 ppm F. Collagen decomposition peaks were at 320–330 ◦ C for the 0ppm, 0.5 ppm, 1ppm, and 2 ppm F groups. This peak shifts slightly to higher temperatures with higher fluorine concentrations (335.7 °C for 5 ppm F and 345.3 °C for 25 ppm F). Unmineralized collagen combusted at 542.3 °C. All values have a standard instrument error of ±0.3 °C.