Table 1.

Specific fragments of oxidatively modified amino acid residues used for tandem mass spectrometry based detection

Residue	Modification	Precursor immonium ion (Da)	Neutral loss (Da)	References
Trp	Bromo	237.002		[155]
		239.001a
	Hydroxy	175.086		[45]
Tyr	Hydroxy	152.071		[45]
	Bromo	213.986		[174]
	Chloro	170.037		[45, 174]
	Nitro	181.061		[175]
	Dinitro	226.046
	Iodo	261.973		[176]
	Diiodo	387.869
Met	Sulfoxide		63.998	[177, 178]
Cys	Sulfinic acid		65.977b	[150]
	Cam sulfoxide		107.004	[179, 180]
	Cam sulfone		122.999

cam carbamidomethylcysteine produced by alkylation with iodoacetamide

^{a 81}Br isotope

^bNegative ionization