Ion counts of peptide D (LH*CDKLHVDPE) adducts, (A) β93Cys-SO-AαC and β93Cys-SO2-AαC adducts and, (B) β93Cys-SO-ABP and β93Cys-SO2-ABP adducts recovered from the Glu-C digests of 1 mole Hb modified with 3, 0.1 and 0.01 mol equivalents of HONH-AαC or HONH-ABP. The level of adducts were determined from the area of total counts of CID-MS2 spectral data analyzed using orbitrap MS analyzer at 30,000 resolving power. (C) Ion counts of peptide D (LH*CDKLHVDPE) of β93Cys-SO2H and β93Cys-SO3H recovered from the Glu-C digests of 1molar Hb modified with 3, 0.1 and 0.01molar excess of HONH-AαC or HONH-ABP. Data are plotted as mean and standard deviation of ion counts (N = 3).