Table 1.
Values of m/z and tentative attribution of lipids detected in negative and positive ion mode by DESI-MS and nESI-MS with DMF:ACN (1:1, v/v) spray solvent system.
| Negative ions (m/z) | Ion molecular formula | Ion description | Tentative attribution** |
|---|---|---|---|
| 227.3* | C14H27O2 | [M−H]− | Myristic acid, FA(14:0) |
| 253.2* | C16H29O2 | Palmitoleic acid, FA(16:1) | |
| 255.2* | C16H31O2 | Palmitic acid, FA(16:0) | |
| 277.2* | C18H29O2 | Linolenic acid, FA(18:3) | |
| 279.2 | C18H31O2 | Linoleic acid, FA(18:2) | |
| 281.2 | C18H33O2 | Oleic acid, FA(18:1) | |
| 283.2* | C18H35O2 | Stearic acid, FA(18:0) | |
| 301.2 | C20H29O2 | Eicosapentaenoic acid, FA(20:5) | |
| 303.2 | C20H31O2 | Arachidonic acid, FA(20:4) | |
| 305.2* | C20H33O2 | Dihomo-γ-Linolenic Acid, FA(20:3) | |
| 327.2 | C22H31O2 | Docosahexaenoic acid, FA(22:6) | |
| 329.3* | C22H33O2 | Clupanodonic acid, FA(22:5) | |
| 355.3 | C24H35O2 | Tetracosahexaenoic acid, FA(24:6) | |
| 465.4 | C27H45O4S | Cholesterol sulfate | |
| 531.4 | C27H47O8S | 5α-cyprinol 27-sulfate | |
| 511 | Dimer of FA(16:0) | ||
| 535 | Dimer of FA(16:0) and FA(18:2) | ||
| 537 | Dimer of FA(16:0) and FA(18:1) | ||
| 563 | Dimer of FA (18:1) | ||
| 603 | Dimer of FA (20:5) | ||
| 582.8 | Dimer of FA(18:1) and FA(20:5) | ||
| 608.9 | Dimer of FA(22:6) and FA(18:1) | ||
| 610.8 | Dimer of FA(22:6) and FA(18:0) | ||
| 654.8 | Dimer of FA(22:6) | ||
| 747.4 | C40H76O10P | [M−H]− | PG(34:1) |
| 766.4 | C43H77NO8P | PE(38:4) | |
| 768.2 | C40H80NO8P***/ C43H79NO8P | [M+Cl]− / [M−H]− | PC(32:0) / PE(38:3) |
| 794.2 | C42H82NO8P | [M+Cl]− | PC(34:1) |
| 818.3 | C44H82NO8P | PC(36:3) | |
| 820.3 | C44H84NO8P | PC(36:2) | |
| 822.3 | C44H86NO8P | PC(36:1) | |
| 834.3 | C46H77NO10P | [M−H]− | PS(40:6) |
| 840.3 | C46H80NO8P | [M+Cl]− | PC(38:6) |
| 842.3 | C46H82NO8P | PC(38:5) | |
| 868.3 | C48H84NO8P | PC(40:6) | |
| 883.4 | C47H80O13P | [M−H]− | PI(38:5) |
| 885.4 | C47H82O13P | PI(38:4) | |
| 887.4 | C47H84O13P | PI(38:3) | |
| 909.4 | C49H82O13P | PI(40:6) | |
| Positive ions (m/z) | Ion molecular formula | Ion description | Tentative attribution** |
| 725.4 | C39H79N2O6P | [M+Na]+ | SM(34:1) |
| 741.4 | C38H71O10P | PG(32:2) | |
| 754.4 | C40H78NO8P | PC(32:1) | |
| 756.5 | C40H80NO8P | PC(32:0) | |
| 760.5 | C42H83NO8P | [M+H]+ | PC(34:1) |
| 780.5 | C42H80NO8P | [M+Na]+ | PC(34:2) |
| 782.5 | C42H82NO8P | PC(34:1) | |
| 798.4 | C42H82NO8P | [M+K]+ | PC(34:1) |
| 806.4 | C44H82NO8P | [M+Na]+ | PC(36:3) |
| 828.4 | C46H80NO8P | PC(38:6) | |
| 835.2 | C47H93N2O6P | SM(42:2) | |
| 844.4 | C48H88NO7P | PC(O-40:5) | |
| 846.4 | C48H96NO8P | [M+H]+ | PC(40:0) |
| 856.3 | C48H84NO8P | [M+Na]+ | PC(40:6) |
| 881.2 | C45H79O13P | PI (36:4) | |
| 909.2 | C47H83O13P | PI(38:4) | |
*
detected as acyl chain residues in MS/MS experiments.
**
Abbreviations: FA = fatty acid; PG = phosphatidylglicerol; PC = phosphatidylcholine; PE = phosphatidylethanolamine; PS = phosphatidylserine; PI = phosphatidylinositol. (C:U) represents the number of carbon atoms (C) and the number of unsaturations (U) of the fatty acid acyl chain.
***
Molecular formula indicated for chlorinated, sodiated or potassiated species does not include the adduct species.