(1) Try to adjust the the capillary voltage: increase it a little bit each time.
If the the mass response of [M＋H2O －Ｈ]－ is decrease, the mass response of [M-H]- increase: then the m/z (563.10761) definitely is the molecular Ion.
If No such change happened, then the m/z (563.10761) definitely is NOT the Molecular Ion.
(2) From my view, the possibility of ［Ｍ＋Ｈ２Ｏ－Ｈ］( belongs to Molecular ion) is very low. Under ESI (-) negative mode, the trend of forming
the ［Ｍ＋ＨＣＯＯmore high.
Doubt the H2O have that much acidity for forming the ion peak.
