Table 2.

Mass values and diagnostic ions for select normal and variant hemoglobins.

Hemoglobin	Variant	a Calculated Protein Mass (Da)	a Protein Mass Shift vs. Normal (Da)	b Potential Diagnostic Product ion	a Calculated Product Ion Mass (Da)	Observed Product ion Mass (Da)	c Error (Da)	Product Ion Mass Shift vs. Normal (Da)	d Error (Da)
Hbβ	-	15857.25	0.00	c34	3584.98	3584.98	0.00	0.00	0.00
HbS	β6 Glu→Val	15827.27	−29.98	c34	3555.01	3555.04	0.03	−29.94	0.04
HbC	β6 Glu→Lys	15856.30	−0.95	c34	3584.03	3584.06	0.03	−0.92	0.03
Hbα	-	15116.88	0.00	y23	2490.37	2490.42	0.05	0.00	0.00
e HbH-W	α122 His→Gln	15107.88	−9.00	y23	2481.37	2481.38	0.01	−9.04	−0.04

^avalues are monoisotopic mass

^bpotential diagnostic ions as per observation in the text

^cerror in mass assignment of product ion

^derror in mass difference of variant

^eHB H-Westmead