Ltq orbitrap elite apparatus

All the chemicals and reagents
used for high-performance liquid chromatography separation coupled
to electrospray-ion trap mass spectrometry (HPLC-ESI-IT-MS) analysis
were purchased from Sigma Aldrich (St. Louis, MO, USA). HPLC-ESI-MS
analyses were performed with a Surveyor HPLC system connected to an
LCQ Advantage mass spectrometer (Thermo Fisher Scientific San Jose,
CA, USA). The chromatographic column was a Vydac C8 reverse phase
(Hesperia, CA, USA) (150 × 2.1 mm, particle diameter 5 μm).
HPLC-high-resolution ESI-MS and MS/MS experiments were carried out
using an Ultimate 3000 Micro HPLC apparatus (Dionex, Sunnyvale, CA,
USA) equipped with a FLM-3000-Flow manager module and coupled to an
LTQ-Orbitrap Elite apparatus (Thermo Fisher). The column was a Zorbax
300SB-C8 (3.5 μm particle diameter; 1.0 × 150 mm).

High-resolution HPLC-ESI-MS/MS experiments were carried out by an Ultimate 3000 RSLC nano system coupled to an LTQ Orbitrap ELITE apparatus (Thermo Fisher Scientific, Waltham, MA, USA). Zorbax 300 SB-C18 (3.5 μm particle diameter; column dimension 1 mm × 150 mm) (Agilent Technologies, Santa Clara, CA, USA) was used as chromato-graphic column. The following eluents were used: (A) 0.1% (v/v) aqueous FA and (B) 0.1% (v/v) FA in ACN/water 80/20 v/v. The ap- plied gradient was: 0–2 min 5% B, 2–40 min from 5 to 70% B (linear), 40–45 min from 70 to 99% B (linear), at a flow rate of 50 μL/min with a total run of 65 min. MS spectra were collected with 120,000 resolution and m/z range from 350 to 2000. In data-dependent acquisition mode the five most intense multiply charged ions were selected and fragmented in ion trap by using CID 35% normalized collision energy. Tuning parameters were: capillary temperature 300 °C, source voltage 4.0 kV.