Fig. 6.
RP-HPLC-ESI(–)-orbital ion trap MS extracted ion chromatograms of the standard PA(34:1), m/z 673.5 (A + C) and PS(36:1), m/z 788.5 (B + D) separated on a Waters X-Bridge C18 (150 × 1.0 mm I.D.; 3.5 μm) column. (A + B) Mobile phase A: ACN/MeOH/H2O (19:19:2) with 0.2% formic acid and 0.028% ammonia; mobile phase B: IPA with 0.2% formic acid and 0.028% ammonia at a flow-rate of 20 μL/min and temperature 50°C. (C) Phosphoric acid added into the mobile phase A and the injector-rinsing solvent. (D) Mobile phase A: IPA/MeOH/H2O (5:1:4) with 0.2% formic acid, 0.028% ammonia, and 5 μM phosphoric acid; mobile phase B: IPA with 0.2% formic acid and 0.028% ammonia at a flow-rate of 20 μL/min and temperature 25°C. {Reproduced with permission from [27]}.