Table 1.
Summary of the specific scans in each lipid class used to identify and quantify individual molecular speciesa
| Lipid class (ref) | Ion format | Scans for class specific prescreen | Scans for identification of acyl chain and/or regioisomers | Preliminary scans for the second step quantitation |
|---|---|---|---|---|
| PC (43) | [M+Li]+ | NLS189.1, −35eV | NLS(59.0+FA), −40eV | NLS183.1, −35eV for polyunsaturated acyl chain containing species NLS59.0, −24eV for plasmalogen species NLS189.1, −35eV for all the other species |
| lysoPC (43) | [M+Na]+ | NLS59.0, −22eV NLS205.0, −34eV |
PIS104.1, −34eV PIS147.1, −34eV |
NLS59.0, −22eV NLS205.0, −34eV |
| PE, lysoPE (18) | [M-H]− [M-H+Fmoc]− ([M+C15H9O2]−) |
PIS196.1, 50eV for [M-H]− NLS222.2, 30eV |
PIS(FA-H), 30eV | NLS222.2, 30eV for [M-H+Fmoc]− |
| PI, lysoPI (23) | [M-H]− | PIS241.1, 45eV | PIS(FA-H), 47eV | PIS241.1, 45eV |
| PS, lysoPS (23) | [M-H]− | NLS87.1, 24eV | PIS(FA-H), 30eV | NLS87.1, 24eV |
| PG, PA, lysoPG, lysoPA (23) | [M-H]− | PIS153.1, 35eV | PIS(FA-H), 30eV | PIS153.1, 35eV |
| CL, mono-lysoCL (33) | [M-2H]2− | Full MS at high resolution | PIS(FA-H) at high resolution, 25eV; NLS(FA-H2O) at high resolution, 22eV | |
| TAG (27) | [M+Li]+ | NLS(FA), −35eV | ||
| Sphingomyelin (43) | [M+Li]+ | NLS213.2, −50eV | NLS(neutral fragments from sphingoid backbone) | NLS213.2, −50eV |
| Ceramide (44) | [M-H]− | NLS(neutral fragments from sphingoid backbone), (e.g., NLS256.2, 32eV for d18:1 non-hydroxyl species) | NLS(neutral fragments from sphingoid backbone), (e.g., NLS256.2, 32eV for d18:1 non-hydroxyl species) | NLS(neutral fragments from sphingoid backbone), (e.g., NLS256.2, 32eV for d18:1 non-hydroxyl species) |
| Hexosyl ceramide (45, 46) | [M+Li]+ | NLS162.2, −50eV | NLS(neutral fragments from sphingoid backbone) | NLS162.2, −50eV |
| Sulfatide (47) | [M-H]− | PIS 97.1, 65eV | NLS(neutral fragments from sphingoid backbone) | PIS97.1, 65eV |
| Sphingoid base-1-phosphate (48) | [M-H]− | PIS79.1, 24eV | PIS79.1, 24eV | |
| Sphingoid base (19) | [M+H]+ | NLS48.0, −18eV | NLS48.0, 18eV | |
| Psychosine (49) | [M+H]+ | NLS180.0, −24eV | NLS180.0, −24eV | |
| Cholesterol (50) | [cholesteryl methoxyacetate +MeOH+Li]+ | PIS97.1, −22eV | PIS97.1, −22eV | |
| Acyl carnitine (51) | [M+H]+ | PIS85.1, −30eV | PIS85.1, −30eV for all species; PIS145.1, −30eV for hydroxyl species | PIS85.1, −30eV |
| Acyl-CoA (16) | [M-H]−, [M-2H]2− [M-3H]3− |
PIS134.0, 30eV | PIS134.0, 30eV | PIS134.0, 30eV |
| 4-hydroxyalkenal (34) | [M+carnosine+H]+ | NLS71.2, −28eV NLS117.2, −26eV |
NLS71.2, −28eV NLS117.2, −26eV |
a
NLS and PIS stand for neutral-loss scan and precursor-ion scan, respectively. FA and (FA-H) denote free fatty acid and fatty acyl carboxylate anion, respectively. The abbreviations of phospholipid classes are given in the text.