Thereafter they are injected using flow injection analysis without LC column, evaluating both electrospray and atmospheric pressure chemical ionisation (APCI).
The strategy is divided into two stages, mass spectrometric ionisation screening and reversed phase LC column screening.
Gel filtration chromatography on a Superdex-200 (GE Healthcare, Tokyo, Japan) fast protein LC column equilibrated with 25 mM HEPES (pH 7.5), 100 mM NaCl and 5 mM dithiothreitol was the final purification step.
LC MS/MS provides three analytical filtering functions: (1) the LC column provides initial separation as each analyte elutes from the column.
Peptides eluted from the LC column were directly electrosprayed into the mass spectrometer with a distal 2 kV spray voltage.
The AdvanceBio oligonucleotide column is the first high-pH, stable, superficially porous particle-based liquid chromatography (LC) column for oligonucleotide analysis.
The HPLC instrument used was Shimadzu HPLC, column type: Phenomenex Luna®, 5 μm Silica(2) 100 Å, LC Column 100 × 4.6 mm in room temperature.
A 1.2 × 100 mm XTerra MS C-18 3.5 μm C-18 reversed-phase LC column (Waters Corporation, Milford, MA) was utilized.
A 20 μL volume of each sample was injected into a Luna 5 μm HILIC 200 Å 250 × 4.6 mm LC column (Phenomenex, Torrance, CA).
This process of precursor selection, dissociation, and fragment ion mass analysis is repetitively performed on analyte species as they elute from the LC column.
The solution was separated on an Xbridge C18 LC column (2.1 × 150 mm, 5 µm) from Waters (Waters Corp., Milford, MA, USA) at a room temperature.
