then ramping from 3% to 46% solvent D (water/ACN/formic acid, 10/90/0.1, v/v/v) over 60 min, then to 90% solvent D over 10 min, flushing the column for 10 min at this buffer composition, and finally decreasing to 100% solvent C in 3 min to re-equilibrate the column for 20 ...