Hplc 1200 series rapid resolution

Oxylipins were extracted as described by Scala et al. (2013 (link)) with slight modifications. Samples were analyzed by liquid chromatography (HPLC 1200 series rapid resolution, Agilent Technologies, Santa Clara, CA, USA) coupled to triple quadrupole (G6410A series triple quadrupole, QqQ, Agilent Technologies, CA, USA) equipped with an electrospray ionization (ESI). Experiments in MRM in negative ion mode [M-H]⁻ were performed and data processed as reported by Ludovici et al. (2014 (link)).

All solvents used for sphingolipids extraction and HPLC/MS analysis were of HPLC/MS grade. Methanol (MeOH), isopropyl alcohol (iPrOH), ethyl acetate (EtOAc), and acetonitrile (ACN) were purchased from Merck (Darmstadt, Germany). Ammonium formate (NH₄HCO₂) was purchased from Sigma Aldrich.
Mass spectrometry analyses were performed by LC (HPLC 1200 series rapid resolution) coupled to a triple quadrupole MS (G6420 series triple quadrupole, QqQ; Agilent Technologies, Santa Clara, CA, USA), with an electrospray ionization source (ESI). Chromatographic column and analysis software were provided by Agilent Technologies (Santa Clara, CA, USA). The temperature was set at 350 °C, the nitrogen flow at 10 L/min, the nebulization pressure at 20 psi, and the voltage at 4000 V.