Table 7.

Performance indices of the four established quantitative calibration models

Quality indicator	Wavelength (cm−1)	LV	Calibration		Cross-validation		Validation		RMSECV/RMSEP
			R C	RMSEC	R CV	RMSECV	R P	RMSEP
Lobetyolin	5500–6300	7	0.9975	1.02 μg/ml	0.9946	1.49 μg/ml	0.9974	1.22 μg/ml	1.2
Total flavonoids	5500–6300	7	0.9835	8.69 μg/ml	0.9748	10.80 μg/ml	0.9759	10.50 μg/ml	1.0
Pigments	5400–6100	9	0.9963	1.31 μg/ml	0.9932	1.78 μg/ml	0.9965	1.43 μg/ml	1.2
Total solid contents	5400–7300	9	0.9993	0.256%	0.9985	0.381%	0.9982	0.433%	0.9

LV: latent variable; R: correlation coefficient; RMSE: root mean squares error; C: calibration; CV: cross-validation; P: prediction