Rapid Quality Identification of Decoction Pieces of Crude and Processed Corydalis Rhizoma by Near-Infrared Spectroscopy Coupled with Chemometrics

Table 2

Results with protopine of NIR spectra pretreatment methods.

Pretreatment	R^2	RMSEC (%)	RMSEP (%)
MSC + spectrum + NS	0.9433	1.2914	1.7347
MSC + 1stD + NS	0.9699	1.0277	1.4866
MSC + 2stD + NS	0.9978	0.3518	0.5573
MSC + spectrum + S-G	0.9419	1.4087	1.7568
MSC + 1stD + S-G	0.9666	1.0771	1.5615
MSC + 2stD + S-G	0.9228	1.6132	1.9441
MSC + 1stD + ND	0.9603	1.1747	1.5371
MSC + 2stD + ND	0.9548	1.2469	1.6983
SNV + spectrum + NS	0.9433	1.3982	1.7144
SNV + 1stD + NS	0.9699	1.0273	1.4836
SNV + 2stD + NS	0.9812	0.5576	0.7452
SNV + spectrum + S-G	0.9419	1.4028	1.7563
SNV + 1stD + S-G	0.9691	1.0328	1.5147
SNV + 2stD + S-G	0.9227	1.6133	1.4275
SNV + 1stD + ND	0.9606	1.1678	1.5336
SNV + 2stD + ND	0.9553	1.2466	1.6872