Fig. 3From: A LC–ESI–MS/MS analysis procedure coupled with solid phase extraction and MeOH extraction method for determination of pyrrolizidine alkaloids in Tussilago farfara and Lithospermi erythrorhzionThe MRM chromatograms of 28 pyrrolizidine alkaloids obtained from LC–MS/MS analysis in the mixed standard solution. Each pair the molecular mass and compound name abbreviations were shown Table 1Back to article page