Rapid Identification of Nine Easily Confused Mineral Traditional Chinese Medicines Using Raman Spectroscopy Based on Support Vector Machine

Table 2

Peak positions and assignments of Raman bands.

Mineral TCMs	Chemical composition	Raman shifts (cm^−1)	Assignment	References
Gypsum fibrosum	CaSO4·2H2O	92∼210	Lattice modes	[29]
		415, 494	ν2 SO4 bending
		619, 672	ν4 SO4 bending
		1009	ν1 SO4 stretching
		1137	ν3 SO4 asymmetric stretching
Alumen	KAl(SO4)2·12H2O	86∼191	Lattice modes	[30]
		443, 461	ν2 SO4^2− symmetric bending
		617	ν4 SO4^2− asymmetric bending
		969, 990	ν1 SO4^2− symmetric stretching
		1097, 1133	ν3 SO4^2− asymmetric stretching
Sal ammoniac	NH4Cl	93∼167	Lattice modes	[31]
		1402	ν4 NH4 bending
		1708	ν2 NH4 bending
Quartz	SiO2	128∼264	Lattice modes	[32]
		355, 395, 410, 464	Si-O bending
		696, 795, 808	Si-O-Si symmetric stretching
		1161	Si-O asymmetric stretching
Natrii sulfas	Na2SO4·10H2O	169, 225	Lattice modes	[33]
		450	ν2 SO4^2− symmetric bending
		620, 633, 648	ν4 SO4^2− asymmetric bending
		989	ν1 SO4^2− symmetric stretching
		1100∼1160	ν3 SO4^2− asymmetric stretching
Natrii sulfas exsiccatus	Na2SO4	80∼160	Lattice modes	[34]
		452, 466	ν2 SO4^2− symmetric bending
		620, 633, 648	ν4 SO4^2− asymmetric bending
		993	ν1 SO4^2− symmetric stretching
		1101, 1131, 1152	ν3 SO4^2− asymmetric stretching
Calcite	CaCO3	154, 280	Lattice modes	[35, 36]
		712	CO3ν4 symmetric deformation
		1086	CO3ν1 symmetric stretching
		1437	CO3ν3 asymmetric stretching
Yellow croaker otolith	CaCO3	150, 178, 202	Lattice modes	[37]
		704	CO3^2−ν4 symmetric deformation
		1083	CO3^2−ν1 symmetric stretching
Borax	Na2B4O7·10H2O	82∼317	Lattice modes	[38]
		352, 386	ν2 BO4 symmetric bending
		462, 487	ν4 BO4 asymmetric bending
		576	ν1 BO4 symmetric stretching
		761	ν2 BO3 symmetric bending
		950	ν1 BO3 symmetric stretching
		1035	ν3 BO4 asymmetric stretching
		1338	ν3 BO3 asymmetric stretching