Table III.

Identification of Oxytocin Degradation Products for pH 4.5, 7.0 and 9.0 Formulations from LC-MS Data Shown in Fig. 8

Peak number	Retention time [min]	m/z	Charge	Assignment
1a	10.4	1,008.42	1+	Mono-deamidation at Asn6 or Gln4a
2a	12.3	1,008.42	1+	Mono-deamidation at Gly9a
3a	12.6	1,008.42	1+	Mono-deamidation at Asn6 or Gln4*
4	15.9	1,007.44	1+	Oxytocin
5	19.3	1,039.41	1+	Trisulfide
6	23.3	1,071.38	1+	Tetrasulfide
7	24.5	975.44	2+	Dimer, bis-deamidated, bis-β-eliminated
8	28.4	975.44	2+	Dimer, bis-deamidated, bis-β-eliminated
9	>30	–	multiple	Larger aggregates and others

^aOnly present in pH 9 samples, assignment based on MS and MS/MS data