Peak assignment

Peak position wave number (cm⁻¹)

F.B

HAP

Alg/Hap

Stretching O-H

3430

3470

3400

Adsorbed water

3400 - 2800

3250

3100

Bending mode, ν₂ of adsorbed water

1658

1650

----

Stretching mode, ν₃ of ${\text{CO}}_3^{2-}$ group

1456

1410

1380

Asymmetric or ν₃ of (PO₄)³⁻ group

1030

1050

----

The O-P-O bands of (PO₄)³⁻ group

604 - 560

630 - 560

552

Asymmetric stretching vibration of the carboxylate (-COO^-) groups

----

----

1630

The C-O-C (cyclic ether) stretching vibration

----

----

1040