Figure 1.
The selective ion monitoring (SIM) chromatograms of 6 compounds and internal standard (IS) in negative mode. (A) 5-CQA; (B) PCA; (C) 3-CQA; (D) EB; (E) 4-CQA; (F) GPS; and (G) IS.
The selective ion monitoring (SIM) chromatograms of 6 compounds and internal standard (IS) in negative mode. (A) 5-CQA; (B) PCA; (C) 3-CQA; (D) EB; (E) 4-CQA; (F) GPS; and (G) IS.