Comparison of peptide identification numbers binned by retention time. The bars indicate peptide identification numbers in each bin. The error bars indicate the SDs of triplicate analyses. ∗p < 0.05. A–C, results of global proteomics with (A) 4% ACN, (B) 2% ACN, and (C) 0% ACN solvent for loading and washing at the desalting step. D–F, results of phosphoproteomics with (D) 4% ACN, (E) 2% ACN, and (F) 0% ACN solvent for loading and washing at the desalting step. ACN, acetonitrile.