Table 2 Typical peak absorption frequencies associated with cystine oxidation products [3, 10]
Chemical functional group | Chemical names | Wavenumber (cm−1) |
|---|---|---|
–SO2–S– | Cystine dioxide (CD) | 1121 |
–SO–S– | Cystine monoxide (CM) | 1071 |
–\({\text{SO}}_{3}^{ - }\) | Cysteic acid (CA) | 1040 |
–S–\({\text{SO}}_{3}^{ - }\) | S-sulfonate | 1022 |