A Useful Strategy to Evaluate the Quality Consistency of Traditional Chinese Medicines Based on Liquid Chromatography and Chemometrics

Figure 3

PCA projection plot for other batches of samples relative to the samples in the reference class. The blue dots represent the samples in the reference class; the black dots refer to the batches of samples with no significant differences to the centroid of the reference class; the red dots denote the batches of samples having significant differences to the centroid of the reference class. Red ellipse is drawn at 95% probability ().