Table 1.

NIR absorbance band assignments for major components of bone

Component	NIR Frequency (cm−1)	Assignment
Water	5100 – 5200	Combination of the O-H stretching band and the O-H bending band [71]
	6900 – 7100	O-H stretching band 1st overtone [71]
Collagen	4608	Combination of the C-H stretching and the C-H deformation[69]
	4896	Combination of Amide A and II [72]
Fat	4273	Combination of CH2 symmetric stretching and bending vibrations [73]
	4344	Combination of CH2 asymmetric stretching and bending vibrations [73]
	5664–5701	1st overtone of CH2 symmetric stretching[73]
	5797	1st overtone of CH2 antisymmetric stretching [73]
Mineral (very small absorbance)	4690, 4673, 4657, 4615, 5200	Surface P-OH: combination of bending and stretching[64]
	7186, 7164, 7145, 7115	Surface P–OH: 2nd overtone (counterparts of the 4690–4615 cm-−1 bands) [64]