Table 2. Fragment ions with C–C bond cleavage of TMS- and TBDMS-derivatized organic acids by CID.
| Organic acids | Precursor ion | Product ion | |||||
|---|---|---|---|---|---|---|---|
| m/z | Carbon skeleton | m/z | Number of organic acid-derived carbons | Carbon skeleton | Estimated chemical formula | Estimated cleavage group from intact molecule | |
| TMS derivatization | |||||||
| Citric acid (4TMS) | 465 | C1-2-3-4-5-6 | 183 | 5 | C1-2-3-4-5 | C8H11O3Si | TMS-COO, TMS-OH and TMS-O |
| Citric acid (4TMS) | 465 | C1-2-3-4-5-6 | 257 | 5 | C1-2-3-4-5 | C10H17O4Si2 | CH3, TMS-COOH and TMS-OH |
| Citric acid (4TMS) | 465 | C1-2-3-4-5-6 | 347 | 5 | C1-2-3-4-5 | C13H27O5Si3 | CH3 and TMS-COOH |
| Citric acid (4TMS) | 465 | C1-2-3-4-5-6 | 273 | 5 | C1-2-3-4-5 | C11H21O4Si2 | TMS-OH and TMS-COOH |
| Citric acid (4TMS) | 363 | C1-2-3-4-5 | 183 | 5 | C1-2-3-4-5 | C8H11O3Si | TMS-COO, TMS-OH and TMS-O |
| Citric acid (4TMS) | 363 | C1-2-3-4-5 | 273 | 5 | C1-2-3-4-5 | C11H21O4Si2 | TMS-COO and TMS-OH |
| Citric acid (4TMS) | 273 | C1-2-3-4-5 | 183 | 5 | C1-2-3-4-5 | C8H11O3Si | TMS-COO, TMS-OH and TMS-O |
| αKG (1MEOX, 2TMS) | 288 | C1-2-3-4-5 | 244 | 4 | C1-2-3-4 | C10H22O2NSi2 | CH3O, CO, and CH3 |
| αKG (1MEOX, 2TMS) | 288 | C1-2-3-4-5 | 170 | 4 | C1-2-3-4 | C7H15NO2Si | CH3O and TMS-COOH |
| Fumaric acid (2TMS) | 245 | C1-2-3-4 | 217 | 3 | C1-2-3 or C2-3-4 | C8H17O3Si2 | CH3 and CO |
| Malic acid (3TMS) | 233 | C2-3-4 | 101 | 2 | C2-3 | C4H9OSi | TMS-COO, TMS-OOH and CH3 |
| Malic acid (3TMS) | 233 | C2-3-4 | 117 | 1 | C4 | C4H9O2Si | Except TMS-COO |
| Malic acid (3TMS) | 233 | C2-3-4 | 143 | 3 | C2-3-4 | C6H11O2Si | TMS-COO, TMS-OH |
| Malic acid (3TMS) | 233 | C2-3-4 | 189 | 2 | C2-3 | C8H21OSi2 | TMS-COO, CH3 and CO |
| Malic acid (3TMS) | 335 | C1-2-3-4 | 307 | 3 | C2-3-4 | C11H27O4Si3 | CH3 and CO |
| Malic acid (3TMS) | 335 | C1-2-3-4 | 263 | 2 | C2-3 | C10H27O2Si3 | CH3, CH2, CO and CO |
| Malic acid (3TMS) | 335 | C1-2-3-4 | 217 | 3 | C2-3-4 | C8H17O3Si2 | CH3 and TMS-COOH |
| Malic acid (3TMS) | 335 | C1-2-3-4 | 117 | 1 | C4 | C4H9O2Si | Except TMS-COO |
| TBDMS derivatization | |||||||
| Citric acid (4TBDMS) | 357 | C1-2-3-4-5 | 225 | 5 | C1-2-3-4-5 | C11H17O3Si | TBDMS-OH, TBDMS-COO, TBDMS-O |
| Citric acid (4TBDMS) | 357 | C1-2-3-4-5 | 313 | 4 | C1-2-3-4 or C2-3-4-5 | C16H33O2Si2 | TBDMS-OH, TBDMS-COO, CO and CH3 |
| Citric acid (4TBDMS) | 431 | C1-2-3-4-5 | 387 | 4 | C1-2-3-4 or C2-3-4-5 | C18H39O3Si3 | TBDMS-OH, TB, CO, CO and CH3 |
| Citric acid (4TBDMS) | 459 | C1-2-3-4-5-6 | 387 | 4 | C1-2-3-4 or C2-3-4-5 | C18H39O3Si3 | TBDMS-OH, TB, CO, CO and CH3 |
| αKG (1MEOX, 2TBDMS) | 346 | C1-2-3-4-5 | 186 | 4 | C1-2-3-4 | C7H12O3NSi | TB, and TBDMS-COO |
| αKG (1MEOX, 2TBDMS) | 346 | C1-2-3-4-5 | 156 | 4 | C1-2-3-4 | C6H10O2NSi | TB, TBDMS-COO and CH3O |
| αKG (1MEOX, 2TBDMS) | 156 | C1-2-3-4 | 112 | 3 | C2-3-4 | C5H10NSi | TB, TBDMS-COO CH3O, CO and CH3 |
| Malic acid (3TBDMS) | 419 | C1-2-3-4 | 217 | 3 | C2-3 | C9H21O2Si2 | TB, TBDMS-COO, CO and CH3 |
| Malic acid (3TDBMS) | 419 | C1-2-3-4 | 391 | 3 | C2-3-4 | C17H39O4Si3 | TB and CO |
| Malic acid (3TDBMS) | 419 | C1-2-3-4 | 403 | 4 | C1-2-3-4 | C17H39O4Si3 | TB and CH3 |
| Malic acid (3TDBMS) | 317 | C2-3-4 | 273 | 2 | C2-3 | C14H33OSi2 | TBDMS-COO, CO and CH3 |