Mass difference ± |
Origin |
0.984016 |
OH ↔ NH2, e.g. de-amidiation, CHNO compounds |
1.99566322 |
F ↔ OH, halogen exchange with hydroxy group (typically -F + OH) |
2.01565 |
± 2H, opening or forming of double bond |
4.955395 |
Na+↔ NH4+, salt adduct |
7.00467078 |
F ↔ CN, halogen exchange with cyano group |
8.96577868 |
Cl ↔ CN, halogen exchange with cyano group |
13.979265 |
O ↔ 2H, e.g. Oxidation follwed by H2O elimination |
14.01565 |
± CH2, alkane chains, waxes, fatty acids, methylation |
14.01565 |
-[C3H6ON] ↔ -[C2H4ON], acrylamide versus iodoacetamide in cysteine
alkylation (gels) |
15.973937 |
Na+↔ K+, salt adduct |
15.977156 |
S ↔ O, sulfur compounds |
15.994915 |
± O, e.g. oxidation/reduction |
17.026549 |
± NH3, ammonium adduct/neutral ammonium loss |
17.026549 |
NH4+ ↔ H+, salt adduct |
17.96611268 |
Cl ↔ OH, halogen exchange with hydroxy group (typically -Cl + OH) |
17.99057822 |
F ↔ H, halogen exchange |
18.010565 |
± H2O, water addition/loss |
18.994581 |
CN ↔ COOH, nitrile compounds |
20.929332 |
K+↔ NH4+, salt adduct |
21.981944 |
Na+↔ H+, salt adduct |
24.995249 |
CN ↔ H, nitrile compounds |
27.010899 |
± HCN, nitrile compounds |
27.994915 |
± CO |
28.006148 |
- 2N, nitrogen loss, e.g. azido compounds (N2) |
28.0313 |
± C2H4, natural alkane chains such as fatty acids |
29.97418 |
NO2 ↔ NH2, nitro compounds |
29.997989 |
-NO, nitroso compounds |
31.972071 |
± S, sulfur compounds |
31.98983 |
± 2O, oxygen loss |
33.021464 |
- NH2OH, loss from hydroxamic acids |
33.96102768 |
Cl ↔ H, halogen exchange |
33.987721 |
± H2S, sulfur compounds |
37.955881 |
K+↔ H+, salt adduct |
37.989162 |
2CN ↔ 2COOH, nitrile compounds |
40.0313 |
+(C3H6O - H2O), acetone condensation after dehydration |
42.010565 |
± COCH2 |
42.04695 |
± C3H6, propylation |
43.005814 |
± CONH (wrong calc. in ref.) |
43.94948442 |
79Br ↔ Cl, halogen exchange (typically -Br +Cl) |
43.98983 |
± CO2 |
45.94743792 |
81Br ↔ Cl, halogen exchange (typically -Br +Cl) |
47.966986 |
± SO, sulfur compounds |
52.9152631 |
79Br ↔ CN, halogen exchange with cyano group |
54.9132166 |
81Br ↔ CN, halogen exchange with cyano group |
56.0626 |
± C4H8, butylation |
58.00548 |
± CO2CH2 |
58.041865 |
+C3H6O, acetone condensation |
61.9155971 |
79Br ↔ OH, halogen exchange with hydroxy group (typically -Br + OH) |
63.9135506 |
81Br ↔ OH, halogen exchange with hydroxy group (typically -Br + OH) |
63.961901 |
± SO2, sulfur compounds |
63.998286 |
-CH3SOH, specific loss from singly oxidized methionine residues |
77.9105121 |
79Br ↔ H, halogen exchange |
79.9084656 |
81Br ↔ H, halogen exchange |
79.956816 |
± SO3, sulfur compounds |
91.93562072 |
I ↔ Cl, halogen exchange (typically -I +Cl) |
97.967381 |
± H2SO4, sulfur compounds |
97.976897 |
± H3PO4, phosphorous compounds |
100.9013994 |
I ↔ CN, halogen exchange with cyano group |
109.9017334 |
I ↔ OH, halogen exchange with hydroxy group (typically -I + OH) |
125.8966484 |
I ↔ H, halogen exchange |
146.05791 |
± [Deoxy-Hexose-H2O, C6O4H10], e.g. Fucose |
162.052825 |
± [Hexose-H2O, C6O5H10], e.g. Glucose, Galactose, Mannose, Fructose |
164.068475 |
± [Deoxy-Hexose-H2O, C6O5H12], e.g. Fucose |
176.03209 |
± [Glucuronic acid-H2O, C6O6H8] |
180.06339 |
± [Hexose, C6O6H12], e.g. Glucose, Galactose, Mannose, Fructose |
194.042655 |
± [Glucuronic acid, C6O7H10] |
203.079374 |
± [HexNAc-H2O, C8O5NH13], N-acetylhexoseamine |
206.05791 |
+ sinapic acid - H2O, (C11H12O5-H2O), MALDI-matrix for proteins, possible
photo- or condensation adduct |
221.089939 |
± [HexNAc, C8O6NH15], N-acetylhexoseamine |
289.073243 |
± [Glutathione-H2O,C10O5N3SH15] |
291.095419 |
± [Neu5Ac-H2O, C11O8NH17], N-acetylneuraminic acid, sialic acid, NANA |
305.068158 |
± [Glutathione+O-H2O, C10O6N3SH15] |
307.083808 |
± [Glutathione, C10O6N3SH17] |
309.105984 |
± [Neu5Ac, C11O9NH19], N-acetylneuraminic acid, sialic acid, NANA |
324.10565 |
± [Sucrose-H2O, C12O10H20] |
342.116215 |
± [Sucrose, C12O11H22] |
484.171011 |
+Tetraphenyl-tetramethyl-trisiloxane, (C28H32O2Si3), ( from silicon-based
diffusion pump oil (DC7040, Dow corning) |
546.186661 |
+Pentaphenyl-trimethyl-trisiloxane, (C33H34O2Si3), ( from silicon-based
diffusion pump oil (DC7050, Dow corning) |