“…An additional function of these labeling reagents is to improve ionization efficiency and glycan stability in both matrix-assisted laser desorption ionization (MALDI) and electrospray ionization (ESI). Several other labeling reagents have also been reported for quantitative glycomics, including 2-aminoacridone (AMAC) (Charlwood, Birrell, Organ, & Camilleri, 1999), 4-aminobenzonitrile (ABN) (Schwaiger, Oefner, Huber, Grill, & Bonn, 1994), 3-aminobenzoic acid (3-AA) (Nakajima, Oda, Kinoshita, Masuko, & Kakehi, 2002) and 3-aminobenzamide (3-AB) (Kakehi, Funakubo, Suzuki, Oda, & Kitada, 1999). …”