Factor analysis of NMR spectral data showing relationship between metabolite profiles and copper exposure. (A) Scores plot, axes 1 and 2. (B) Scores plot following Kaiser varimax rotation, axes 2 and 3. Data are shown for both individual samples and for dose group means ± standard deviation (SD); groups are joined in dose order by dashed line. (C) Loadings plot, axes 1 and 2. (D) Loadings plot following varimax rotation, axes 2 and 3. Loadings for individual metabolites are identified by abbreviations given in Table 1.