Simultaneous Determination of C18 Fatty Acids in Milk by GC-MS
Abstract
:1. Introduction
2. Materials and Methods
2.1. Milk Samples
2.2. Chemicals and Reagents
2.3. Sample Pretreatment
2.4. GC-MS Analysis
2.5. Method Validation
2.6. Statistical Analysis
3. Results and Discussion
3.1. The Species of Detected C18 FAs
3.2. Methylation
3.3. Method Validation
3.4. The Analysis of C18 FAs in Milk Samples
4. Conclusions
Author Contributions
Funding
Institutional Review Board Statement
Informed Consent Statement
Data Availability Statement
Conflicts of Interest
References
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No. | FAMEs | Retention Time (min) | Windows | Quantification Ion (m/z) | Qualification Ion (m/z) | Dwell Time (ms) | ||
---|---|---|---|---|---|---|---|---|
1 | C18:0 | 42.032 | 1 | 74 | 87 | 143 | 298 | 20 |
2 | C18:1 t6 | 43.203 | 2 | 264 | 97 | 222 | 180 | 20 |
3 | C18:1 t9 | 43.305 | ||||||
4 | C18:1 t11 | 43.466 | ||||||
5 | C18:1 c6 | 43.710 | ||||||
6 | C18:1 c8 | 43.712 | ||||||
7 | C18:1 c9 | 43.848 | ||||||
8 | C18:1 c11 | 44.118 | ||||||
9 | C18:1 c12 | 44.337 | ||||||
10 | C18:2 t9,t12 | 45.502 | 3 | 81 | 95 | 294 | 263 | 20 |
11 | C18:2 c9,t12 | 46.17 | ||||||
12 | C18:2 t9,c12 | 46.446 | ||||||
13 | C18:2 c9,c12 | 46.839 | ||||||
14 | C18:3 t9,t12,t15 | 48.215 | 4 | 79 | 93 | 121 | 292 | 20 |
15 | C18:3 t9,t12,c15 | 48.988 | ||||||
16 | C18:3 t9,c12,t15 | |||||||
17 | C18:3 c6,c9,c12 | 49.139 | ||||||
18 | C18:3 c9,t12,t15 | 49.325 | ||||||
19 | C18:3 c9,c12,t15 | |||||||
20 | C18:3 c9,t12,c15 | 49.937 | ||||||
21 | C18:3 t9,c12,c15 | 50.057 | ||||||
22 | C18:3 c9,c12,c15 | 50.438 | ||||||
23 | C18:2 c9,t11 | 51.015 | 5 | 81 | 95 | 294 | 263 | 20 |
24 | C18:2 t10,c12 | 51.525 |
FAMEs | Regression Equation | Linear Range (μg/mL) | R2 | LOD (μg/L) | LOQ (μg/L) | Intra-Day RSD (%) | Inter-Day RSD (%) |
---|---|---|---|---|---|---|---|
C18:0 | y = 117,066x − 53,301 | 0.60~400 | 1.0000 | 9.0 | 30.1 | 2.5 | 3.8 |
C18:1 t6 | y = 12,851x + 592.45 | 0.60~60 | 1.0000 | 156.7 | 522.3 | 3.7 | 2.7 |
C18:1 t9 | y = 12,895x + 1385.3 | 0.60~60 | 0.9999 | 157.3 | 524.4 | 4.8 | 4.6 |
C18:1 t11 | y = 12,430x − 955.05 | 0.60~60 | 0.9993 | 149.4 | 498.0 | 3.6 | 2.8 |
C18:1 c6/C18:1 c8 | y = 12,696x + 505.85 | 0.60~60 | 0.9999 | 158.9 | 529.6 | 1.9 | 2.1 |
C18:1 c9 | y = 12,446x − 858.17 | 0.60~400 | 1.0000 | 161.4 | 538.0 | 2.1 | 3.3 |
C18:1 c11 | y = 12,254x + 1154 | 0.60~60 | 0.9999 | 162.3 | 541.2 | 2.1 | 2.1 |
C18:1 c12 | y = 12072x − 296.45 | 0.60~60 | 0.9997 | 168.8 | 562.7 | 2.7 | 2.9 |
C18:2 t9,t12 | y = 49,383x + 8749 | 0.35~60 | 0.9999 | 84.9 | 283.0 | 2.5 | 3.4 |
C18:2 c9,t12 | y = 43,275x − 5604.1 | 0.35~60 | 0.9989 | 95.8 | 319.3 | 2.1 | 2.5 |
C18:2 t9,c12 | y = 41,591x − 6525.4 | 0.35~60 | 0.9999 | 98.1 | 326.9 | 4.9 | 3.9 |
C18:2 c9,c12 | y = 36,584x − 1898.1 | 0.35~60 | 1.0000 | 103.0 | 343.4 | 2.0 | 2.4 |
C18:2 c9,t11 | y = 43,267x − 6093.4 | 0.35~60 | 0.9989 | 96.5 | 321.6 | 1.9 | 2.8 |
C18:2 t10,c12 | y = 41,715x − 7973 | 0.35~60 | 0.9986 | 100.6 | 335.2 | 2.2 | 3.2 |
C18:3 t9,t12,t15 | y = 84,286x − 9165.8 | 0.15~20 | 0.9999 | 37.8 | 125.8 | NA | NA |
C18:3 t9,t12,c15/C18:3 t9,c12,t15 | y = 86254x − 7942.8 | 0.15~20 | 1.0000 | 37.1 | 123.6 | NA | NA |
C18:3 c6,c9,c12 | y = 88193x − 13659 | 0.15~20 | 0.9998 | 43.7 | 145.5 | 1.8 | 2.6 |
C18:3 c9,t12,t15/C18:3 c9,c12,t15 | y = 72766x − 5435.2 | 0.15~20 | 1.0000 | 44.7 | 148.9 | 2.6 | 3.9 |
C18:3 c9,t12,c15 | y = 50915x + 688.36 | 0.15~20 | 0.9999 | 42.8 | 142.5 | 4.6 | 3.9 |
C18:3 t9,c12,c15 | y = 72954x − 1137.6 | 0.15~20 | 0.9997 | 41.6 | 138.8 | 4.2 | 3.9 |
C18:3 c9,c12,c15 | y = 85866x + 16879 | 0.15~20 | 0.9986 | 30.4 | 101.2 | 1.9 | 2.6 |
Spiked Level (μg/mL) | ||||||
---|---|---|---|---|---|---|
Tags | 20 | 100 | 400 | |||
Recovery (%) | CV (%) | Recovery (%) | CV (%) | Recovery (%) | RSD (%) | |
C18:1 c9 | 103.3 | 2.0 | 104.1 | 3.3 | 95.5 | 5.1 |
C18:2 c9,c12 | 102.7 | 3.3 | 105.1 | 2.5 | 105.8 | 1.8 |
C18:3 c6,c9,c12 | 98.9 | 3.1 | 99.5 | 4.5 | 103.2 | 4.2 |
C18:3 c9,c12,c15 | 104.4 | 3.7 | 99.3 | 3.7 | 100.2 | 4.3 |
Raw Milk | UHT Milk | PAS Milk | |
---|---|---|---|
C18:0 | 3026.3 ± 374.1 | 2707.5 ± 230.6 | 2717.34 ± 240.4 |
C18:1 t6 | 78.5 ± 10.6 | 80.7 ± 11.7 | 78.2 ± 8.9 |
C18:1 t9 | 79.2 ± 15.0 | 70.9 ± 10.9 | 77.9 ± 12.4 |
C18:1 t11 | 234.9 ± 36.5 | 227.0 ± 38.6 | 250.8 ± 54.6 |
C18:1 c6/C18:1 c8 | 241.6 ± 35.6 | 219.3 ± 27.2 | 232.8 ± 32.2 |
C18:1 c9 | 6086.4 ± 631.2 | 5805.3 ± 543.7 | 5722.6 ± 466.7 |
C18:1 c11 | 180.6 ± 34.0 | 199.2 ± 8.1 | 196.8 ± 20.2 |
C18:1 c12 | 135.4 ± 20.7 | 123.2 ± 15.9 | 130.5 ± 18.1 |
C18:2 t9,t12 | 39.7 ± 8.1 | 37.4 ± 4.1 | 35.4 ± 6.8 |
C18:2 c9,t12 | 24.3 ± 5.6 | 23.9 ± 3.0 | 20.3 ± 4.0 |
C18:2 t9,c12 | 9.2 ± 1.9 | 13.6 ± 2.8 | 10.2 ± 1.7 |
C18:2 c9,c12 | 898.1 ± 112.7 | 773.9 ± 76.9 | 805.1 ± 53.5 |
C18:2 c9,t11 (CLA) | 114.4 ± 18.7 | 106.2 ± 14.4 | 112.0 ± 17.7 |
C18:2 t10,c12 (CLA) | 21.3 ± 4.4 | 19.7 ± 2.3 | 25.4 ± 0.7 |
C18:3 t9,t12,t15 | NA | NA | NA |
C18:3 t9,t12,c15/C18:3 t9,c12,t15 | NA | NA | NA |
C18:3 c6,c9,c12 | 22.7 ± 2.1 | 19.6 ± 1.4 | 23.2 ± 1.0 |
C18:3 c9,t12,t15/C18:3 c9,c12,t15 | 4.7 ± 0.9 | 4.5 ± 0.5 | 5.6 ± 0.17 |
C18:3 c9,t12,c15 | 3.3 ± 0.8 | 3.9 ± 0.4 | 3.6 ± 0.3 |
C18:3 t9,c12,c15 | 3.5 ± 0.5 | 3.3 ± 0.3 | 3.3 ± 0.2 |
C18:3 c9,c12,c15 | 82.3 ± 15.1 | 70.8 ± 8.0 | 73.3 ± 10.7 |
Cis/Trans C18:1 | 17.3 ± 1.4 | 17.0 ± 1.7 | 15.1 ± 3.8 |
∑ C18:1 | 7036.5 ± 689.4 | 6725.4 ± 601.7 | 6689.5 ± 497.4 |
∑ C18:2 | 971.2 ± 123.4 | 848.7 ± 84.2 | 871.1 ± 58.1 |
∑ C18:3 | 118.9 ± 12.7 | 102.5 ± 8.1 | 102.5 ± 25.1 |
∑ CLA | 135.7 ± 17.7 | 125.9 ± 14.8 | 137.4 ± 17.7 |
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Chen, M.; Zhang, Y.; Wang, F.; Zheng, N.; Wang, J. Simultaneous Determination of C18 Fatty Acids in Milk by GC-MS. Separations 2021, 8, 118. https://doi.org/10.3390/separations8080118
Chen M, Zhang Y, Wang F, Zheng N, Wang J. Simultaneous Determination of C18 Fatty Acids in Milk by GC-MS. Separations. 2021; 8(8):118. https://doi.org/10.3390/separations8080118
Chicago/Turabian StyleChen, Meiqing, Yangdong Zhang, Fengen Wang, Nan Zheng, and Jiaqi Wang. 2021. "Simultaneous Determination of C18 Fatty Acids in Milk by GC-MS" Separations 8, no. 8: 118. https://doi.org/10.3390/separations8080118