Table 1.
Experimental conditions and validation data for the GC/MS analysis of fatty acids.
| Precision (RSD)d | ||||||||
|---|---|---|---|---|---|---|---|---|
| Fatty Acid | [M-H]-m/z | tRa (min) | INT STDb | SIM Group | LODc (pg) | Intra-day | Inter-day | R2e |
| Lauric Acid (12:0) | 199 | 3.84 | 12:0-d3 | 1 | 0.1 | 12 | 10 | 0.998 |
| 12:0-d3 | 202 | 3.81 | - | 1 | - | - | - | - |
| Myristic Acid (14:0) | 227 | 5.35 | 14:0-d3 | 2 | 0.1 | 5 | 9 | 0.999 |
| 14:0-d3 | 230 | 5.33 | - | 2 | - | - | - | - |
| Pentadecanoic Acid (15:0) | 241 | 6.11 | 15:0-d3 | 2 | 0.1 | 10 | 7 | 0.999 |
| 15:0-d3 | 244 | 6.09 | 2 | - | - | - | - | |
| Palmitic Acid (16:0) | 255 | 6.87 | 16:0-d3 | 3 | 0.1 | 8 | 8 | 0.992 |
| 16:0-d3 | 258 | 6.84 | - | 3 | - | - | - | - |
| Palmitoleic Acid (16:1) | 253 | 6.67 | 16:0-d3 | 3 | 0.75 | 9 | 15 | 0.994 |
| Margaric Acid (17:0) | 269 | 7.60 | 17:0-d3 | 3 | 0.1 | 9 | 15 | 0.999 |
| 17:0-d3 | 272 | 7.58 | - | 3 | - | - | - | - |
| Heptadecaenoic Acid (17:1) | 267 | 7.42 | 17:0-d3 | 3 | 5 | 12 | 16 | 0.996 |
| Stearic Acid (18:0) | 283 | 8.32 | 18:0-d3 | 4 | 0.1 | 7 | 11 | 0.994 |
| 18:0-d3 | 286 | 8.30 | - | 4 | - | - | - | - |
| Oleic Acid (18:1) | 281 | 8.08 | 18:1-d2 | 4 | 0.1 | 8 | 12 | 0.988 |
| 18:1-d2 | 283 | 8.08 | - | 4 | - | - | - | - |
| Linoleic Acid (18:2) | 279 | 8.02 | 18:2-d4 | 4 | 0.1 | 9 | 12 | 0.983 |
| 18:2-d4 | 283 | 8.01 | - | 4 | - | - | - | - |
| α-linolenic Acid (18:3) | 277 | 7.82 | 18:2-d4 | 4 | 1 | 9 | 10 | 0.998 |
| γ-linolenic Acid (18:3) | 277 | 8.06 | 18:2-d4 | 4 | 1 | 9 | 7 | 0.998 |
| Stearidonic Acid (18:4) | 275 | 7.85 | 18:2-d4 | 4 | 5 | 6 | 8 | 0.997 |
| Arachidic Acid (20:0) | 311 | 9.69 | 20:0-d3 | 5 | 5 | 8 | 8 | 0.999 |
| 20:0-d3 | 314 | 9.68 | - | 5 | - | - | - | - |
| Eicosadienoic Acid (20:2) | 307 | 9.43 | 20:4-d8 | 5 | 5 | 7 | 12 | 0.994 |
| 11,14,17-Eicosatrienoic Acid (20:3) | 305 | 9.08 | 20:4-d8 | 5 | 5 | 6 | 10 | 0.998 |
| Bishomo-γ-linolenic Acid (20:3) | 305 | 9.24 | 20:4-d8 | 5 | 1 | 6 | 13 | 0.997 |
| 5,8,11-Eicosatrienoic Acid (20:3) | 305 | 9.46 | 20:4-d8 | 5 | 1 | 5 | 8 | 0.994 |
| Arachidonic Acid (20:4) | 303 | 9.02 | 20:4-d8 | 5 | 0.1 | 7 | 12 | 0.998 |
| 20:4-d8 | 311 | 8.99 | - | 5 | - | - | - | - |
| Eicosapentaenoic Acid (20:5) | 301 | 9.05 | 20:5-d5 | 5 | 0.5 | 7 | 8 | 0.999 |
| 20:5-d5 | 306 | 9.02 | - | 5 | - | - | - | - |
| Behenic Acid (22:0) | 339 | 10.98 | 22:0-d3 | 6 | 5 | 14 | 15 | 0.999 |
| 22:0-d3 | 342 | 10.97 | - | 6 | - | - | - | - |
| Cis-Erucic Acid (22:1) | 337 | 10.80 | 22:0-d3 | 6 | 0.75 | 9 | 9 | 0.994 |
| Docosadienoic Acid (22:2) | 335 | 10.76 | 22:0-d3 | 6 | 5 | 12 | 15 | 0.997 |
| Docosatrienoic Acid (22:3) | 333 | 10.78 | 22:6-d5 | 6 | 10 | 10 | 14 | 0.989 |
| Docosatetraenoic Acid (22:4) | 331 | 10.39 | 22:6-d5 | 6 | 5 | 8 | 15 | 0.997 |
| Docosapentaenoic Acid (22:5) | 329 | 10.42 | 22:6-d5 | 6 | 0.5 | 4 | 15 | 0.996 |
| Docosahexaenoic Acid (22:6) | 327 | 10.23 | 22:6-d5 | 6 | 0.5 | 7 | 9 | 0.998 |
| 22:6-d5 | 332 | 10.20 | - | 6 | - | - | - | - |
| Tricosanoic Acid (23:0) | 353 | 11.60 | 24:0-d4 | 7 | 0.25 | 13 | 9 | 0.999 |
| Lignoceric Acid (24:0) | 367 | 12.18 | 24:0-d4 | 7 | 1 | 7 | 8 | 0.999 |
| 24:0-d4 | 371 | 12.17 | - | 7 | - | - | - | - |
| Cis-Selacholeic Acid (24:1) | 365 | 12.04 | 24:0-d4 | 7 | 1 | 11 | 17 | 0.982 |
| Cerotic Acid (26:0) | 395 | 12.93 | 26:0-d4 | 8 | 0.5 | 14 | 10 | 0.998 |
| 26:0-d4 | 399 | 12.92 | - | 8 | - | - | - | - |
tR, retention time.
Not all deuterated standards are commercially available. Shown is the list of deuterated analogs we are currently employing as internal standards (INT STD). The INT STD are listed in reference to the corresponding fatty acids for which they were used for quantification purpose.
The lower limit of detection (LOD) refers to the actual amount loaded onto the column.
The analytical precision was determined in triplicates for both intra- and inter-day precision and expressed as the relative standard deviation (RSD).
The linearity of the response was determined for calibration curves in the range of 0.003 ng/μl to 10 ng/μl and an GC injection volume of 1 μl. Linear regression analysis was performed and the linear regression coefficient (R2) was computed.