6120 single quadrupole lc ms system

Liquid chromatography-mass spectrometry (LC-MS) with an electrospray ionization (ESI) interface was used to verify the production of cGAMP. The Agilent Technologies 1260 Infinity II LC System was coupled to Agilent Technologies 6120 Single Quadrupole LC/MS System (Agilent Technologies Inc., Santa Clara, CA, USA) and further equipped with a Diode Array Detector (1260 DAD HS, Agilent Technologies Inc., Santa Clara, CA, USA), Multicolumn Thermostat (1260 MCT, Agilent Technologies Inc., Santa Clara, CA, USA), Degasser (1260 Degasser, Agilent Technologies Inc., Santa Clara, CA, USA), Multisampler (1260 Multisampler), Binary Pump (1260 Binary Pump, Agilent Technologies Inc., Santa Clara, CA, USA) and an Agilent Poroshell 120 EC-C18 (4.6 × 100 mm, 2.7 μm particle size) column. Sample volumes of 5 μL were injected and separated by a gradient of mobile phase A (0.1 % formic acid) and mobile phase B (acetonitrile) (0 min 5% A, 95% B; 7 min 95% A, 5% B; 9 min 5% A, 95% B; 14 min 5% A, 95% B). The flow rate was set to 1 mL min⁻¹ at a column temperature of 40 °C and a detection wavelength of 254 nm. Measured masses ranged from 100 to 1000 m/z. The gas chamber was heated to 350 °C with a gas flow of 12 L min⁻¹. The capillary voltage was set to 3 kV and the nebulizer pressure to 35 psi.