Table 3.

The ¹⁸O/¹⁶O ratios calculated from zoom scans for the tryptic digest of the four protein mixture with an expected ¹⁸O/¹⁶O ratio of 3. Peptides that occur in multiple charge states are listed separately for each charge state

Peptide	Number	Charge	Ratio	Efficiency
Myoglobin
ALELFR	6	1	2.02	0.84
LFTGHPETLEK	5	2	2.50	0.79
LFTGHPETLEKFDK	1	3	1.50	0.87
VEADIAGHGQEVLIR	6	2	2.85	0.86
VEADIAGHGQEVLIR	4	3	2.16	0.77
HGTVVLTALGGILK	10	2	2.46	0.87
protein mean			2.25	0.83
standard deviation			0.47	0.04
coefficient of variation			0.21
Protein Tyrosine Phosphatase - 1β
FSYLAVIEGAK	11	2	2.29	0.83
FSYLAVIEGAK	2	1	2.48	0.77
LHQEDNDYINASLIK	6	2	2.87	0.72
LHQEDNDYINASLIK	1	3	2.91	0.75
DVSPFDHSR	7	2	2.41	0.76
ESGSLSPEHGPVVVHCSAGIGR	4	3	2.12	0.87
MGLIQTADQLR	2	2	1.93	0.86
protein mean			2.43	0.80
standard deviation			0.36	0.06
coefficient of variation			0.15
Glyceraldehyde-3-Phosphate Dehydrogenase
GAAQNIIPASTGAAK	9	2	2.61	0.83
VPRPNVSVVDLTCR	4	2	2.65	0.73
protein mean			2.63	0.78
standard deviation			0.03	0.07
coefficient of variation			0.01
Vascular Endothelial Growth Factor
FMDVYQR	4	2	2.36	0.68
HLFVQDPQTCK	2	2	3.26	0.69
QLELNER	1	2	1.10	0.91
protein mean			2.24	0.76
standard deviation			1.08	0.13
coefficient of variation			0.48