Table 2.
Identification of phytosterols and lipids in guava seed oil using TMS derivatization-GC/MS.
| Peak No. |
TR (min) |
TIC | Exact Mass (g/mol) |
Molecular Formula | Observed Mass (m/z) |
Error (%) |
Identification |
|---|---|---|---|---|---|---|---|
| 1 | 13.25 | 2277755 | 284.5 | C18H36O2 | 284 | −0.18 | Ethyl palmitate |
| 2 | 14.83 | 2423828 | 308.5 | C20H36O2 | 308 | −0.16 | Ethyll linolenate |
| 3 | 14.89 | 5411461 | 310.5 | C20H38O2 | 310 | −0.16 | Ethyl linoleate |
| 4 | 15.12 | 359612 | 312.5 | C20H40O2 | 312 | −0.16 | Ethyl stearate |
| 5 | 17.77 | 3836542 | 352.6 | C18H32O2 | 353 | 0.11 | Linoleic acid TMS |
| 6 | 18.10 | 17168 | 350.6 | C18H30O2 | 352 | 0.4 | Linolenic acid TMS |
| 7 | 20.41 | 18788155 | 372.7 | C27H48 | 372 | −0.19 | Cholestane |
| 8 | 23.44 | 452445 | 486.9 | C29H50O | 484 | −0.6 | β-Sitosterol TMS |
| 9 | 23.70 | 770310 | 485.8 | C29H48O | 485 | −0.16 | Stigmasterol TMS |
| 10 | 24.37 | 12299199 | 472.9 | C28H48O | 472 | −0.19 | Campesterol TMS |
| 11 | 25.99 | 324939 | - | - | - | - | Unknown |
Abbreviations: m/z = mass to charge ration, TIC = total ion count, TMS = trimethylsilyl, TR = retention time.