Property Test of Phosphate and Hydroxyl Groups from Lates Carcarifer Fish Scale as a Candidate for Synthetic Hydroxyapatite using the FTIR Method

In Indonesia, the market price of Synthetic hydroxyapatite, Ca₁₀(PO₄)₆(OH)₂ reaches 1.5 million per 5 milligrams and its availability still depends on imported products. To solve this problem, alternative materials can be used, such as Lates calcarifer fish scales. Phosphate (PO₄)₃- and hydroxyl (−OH) groups are functional groups of synthetic hydroxyapatites. The presence of phosphate (PO₄)₃- and hydroxyl (−OH) groups in the sample can indicate the presence of hydroxyapatite. Therefore, phosphate and hydroxyl groups can be used as test parameters for the property test. In this study, the phosphate and hydroxyl characteristics of the Lates calcarifer fish scales group were compared with the “ALDRICH” chemical synthetic hydroxyapatite group using the FTIR analysis method. Objectives to explain whether the scales of Lates calcarifer fish can be used as a synthetic hydroxyapatite candidate and to analyze the characteristics of the phosphate and hydroxyl groups produced from Lates calcarifer fish scales. FTIR or Fourier-transform Infrared Spectroscopy analysis method was used by comparing the peak image of the phosphate and hydroxyl groups between the Lates calcarifer fish scales group and the “ALDRICH” chemical synthetic hydroxyapatite control group on the wave ranges of 1350–1250, 1050–990, 1240–1190/995–850, 1100–1000 for phosphate groups and on the wave ranges of 3650–3600, 3570–3200, 3400–2400 for hydroxyl groups. The Lates calcarifer fish scales group showed that the peaks of the phosphate (PO₄)₃₋ and hydroxyl (−OH) groups had the same wave range as the synthetic hydroxyapatite control group “ALDRICH”, namely in the 850–995 cm-, 990–1050 cm-/1100–1000 cm-, and 3200–3570 cm- wave ranges. Lates calcarifer fish scales can be used as a candidate for synthetic hydroxyapatite.