Glycomic MS Analysis via PGC Nano-Chip

Details of the glycomic MS analysis have been described previously ((Wu et al., 2010 (link); Wu et al., 2011 (link))). Glycan samples were reconstituted with 30 μl nanopure water and analyzed using an Agilent 6520 Accurate Mass Q-TOF LC/MS equipped with a PGC nano-chip (Agilent Technologies, CA, United States). The glycan separation was performed at a constant flow rate of 300 nl min −1, and a binary gradient was applied using (A) 0.1% (v/v) formic acid in 3% acetonitrile and (B) 1% (v/v) formic acid in 90% acetonitrile: 0–2 min, 0–0% (B); 2–20 min, 0–16% (B); 20–40 min, 16%–72% (B); 40–42 min, 72–100% (B); 42–52 min, 100–100% (B); 52–54 min, 100–0% (B); 54–65 min, 0–0% (B). MS spectra within the mass range of m/z 600–2000 were collected at a rate of 1.5 s per spectrum in positive ionization mode. The most abundant precursor ions in each MS1 spectrum were subjected to fragmentation through collision-induced dissociation (CID) based on the equation V collision = 1.8 × (m/z)/100–2.4 V.