Peak assignments for lipids^a.

	Frequency (cm−1)	Assignment
Region I	2800–3100	ν(CH), νas(CH3), νs(CH3), νas(CH2), νs(CH2)
Region II	1600–1800	ν(C C), ν(C O)
Region III	1400–1500	b(CH2/CH3), sc(CH2/CH3), b(CH2)
Region IV	1200–1300	t(CH2), df(CH)
Region V	1050–1200	ν(C–C), ν(P–O)
Region VI	800–1050	b(CH), skeletal(C–O–O), νasN+(CH3)3
Region VII	500–700	ν sN+(CH3)3, cholesterol ring df, df(C O–O), b(CH2) ring

^a ν: stretching (s: symmetric, as: asymmetric), b: bending, sc: scissoring, t: twisting, df: deformation, skel: skeletal.