Table 3.
Characteristic ions [m/z (relative intensity)] in the spectra of methyl esters of N,N′-di(trifluoroacetyl)- (A), N-α -methyl-N,N′di(trifluoroacetyl)- (B), N-methyl-N,N′-di(trifluoroacetyl)- (C) and N,N′-dimethyl-N,N′-di(trifluoroacetyl)- (D)-l-lysine.
| Ions | A | B | C | D |
|---|---|---|---|---|
| M+• | 352 (0) | 366 (0.3) | 366 (0.4) | 380 (0.5) |
| [M–CH3OH]+ • | 320 (7) | 334 (1) | 334 (11) | 348 (8) |
| [M–COOCH3]+ | 293 (4) | 307 (3) | 307 (3) | 321 (26) |
| [M–COCF3]+ | 255 (0.1) | 269 (0.4) | 269 (3) | 283 (3) |
| [M–COOCH3–HN(CH3)COCF3]+ | 180 (100) | 180 (100) | 180 (20) | 194 (17) |
| [HN(COCF3)=CH2]+ | 126 (27) | 126 (15) | 126 (4) | 126 (3) |
| [CH3N(COCF3)=CH2]+ | 140 (3) | 140 (12) | 140 (100) | 140 (100) |
| [HC≡N–CH3]+ (a) | 42 (2) | 42 (17) | 42 (10) | 42 (29) |
| [CF3–N≡C–CH3]+ (b) | 110 (2) | 110 (15) | 110 (6) | 110 (31) |
| [C5H7]+ | 67 (19) | 67 (20) | 67 (16) | 67 (23) |
| [CF3]+ | 69 (18) | 69 (14) | 69 (19) | 69 (19) |