Tsq quantum ultra am mass spectrometer

Bis-PFB ester derivatives of the 2-HG enantiomers were separated using a Chiralpak AD-H column (250 × 4.6 mm i.d., 5 μm; Daicel Chemical Industries, Ltd., Tokyo, Japan) at a flow rate of 1 mL/min. Solvent A was hexanes, and solvent B was IPA/MeOH (1:1; v/v). The linear gradient was as follows: 1% B for 3 min, increased to 60% B over 32 min, and held for 4 min, down to 1% B over 1 min prior to a 5 min equilibration. The separation was performed at 30 °C, and a postcolumn addition (0.75 mL/min MeOH) was used. MS analysis was conducted on a Thermo Scientific TSQ Quantum Ultra AM mass spectrometer (Thermo Scientific, San Jose, CA, USA) equipped with an APCI source operating in negative mode. The TSQ Quantum operating conditions were as follows: vaporizer temperature, 350 °C; heated capillary temperature, 300 °C; and corona discharge needle, 30 μA. The sheath gas (nitrogen) and auxiliary gas (nitrogen) pressures were 35 and 10 (arbitrary units), respectively. Collision-induced dissociation used argon as the collision gas at 1.5 mTorr.