Table 2.
Comparison between the On-Column Limit of Detection (LOD) of 3-Picolylamide (PA), 3-Picolinyl Ester (PE), and Dimethylaminoethyl Ester (DMAE) Derivatives of FAs Analyzed by Orbitrap (Exactive) and Tandem (TSQ) Mass Spectrometersa
| name | FA-PA derivatives
|
FA-PE derivatives
|
FA-DMAE derivatives
|
||||||
|---|---|---|---|---|---|---|---|---|---|
| tR (min) | orbitrap LOD (fmol) | TSQ LOD (fmol) | tR (min) | orbitrap LOD (fmol) | TSQ LOD (fmol) | tR (min) | orbitrap LOD (fmol) | TSQ LOD (fmol) | |
| OA | 8.6 | 11 | 280 | 9.0 | 44 | 84 | 5.8 | 30 | 180 |
| PLA | 3.6 | 7 | 30 | 6.0 | 43 | 63 | 2.8 | 22 | 30 |
| LA | 4.7 | 6 | 96 | 6.0 | 20 | 81 | 3.5 | 22 | 70 |
| EDA | 9.4 | 8 | 98 | 9.6 | 11 | 34 | 6.8 | 37 | 65 |
| AA | 4.6 | 9 | 101 | 5.4 | 20 | 176 | 3.4 | 63 | 167 |
| ALA | 2.9 | 25 | 55 | 4.4 | 30 | 165 | 2.3 | 13 | 39 |
| EPA | 2.9 | 20 | 38 | 3.6 | 21 | 106 | 2.2 | 24 | 190 |
| DPA | 5.5 | 15 | 89 | 6.1 | 64 | 70 | 3.8 | 135 | 62 |
| DHA | 4.3 | 4 | 40 | 4.4 | 42 | 140 | 3.2 | 13 | 23 |
| SA | 11.3 | 5 | 130 | 14.0 | 112 | 135 | 9.7 | 26 | 148 |
| PA | 7.0 | 20 | 138 | 8.9 | 35 | 59 | 4.8 | 34 | 97 |
| MA | 2.9 | 13 | 28 | 5.7 | 12 | 45 | 2.4 | 28 | 23 |
| α-ESA | 3.9 | 1.3 nmol | NDb | 5.2 | ND | ND | 2.9 | ND | ND |
| cisPA | 2.6 | 8.4 nmol | ND | 3.3 | ND | ND | 2.1 | ND | ND |
a
The abbreviation of each analyte is shown in Table 1.
b
ND: Not determined.