Table 2.
MRM-parameters and internal standards used for the analysis of amino acids
| Amino acid | RT (min) | MRM-transition (m/z) | Cone voltage (V) | Collision energy (V) | Internal standard | |
|---|---|---|---|---|---|---|
| 1 | Tryptophan | 2.6 | 205.1 → 146.0 | 18 | 18 | indole-D5-tryptophan |
| 2 | Phenylalanine | 2.6 | 166.1 → 120.1 | 20 | 15 | ring-D5-phenylalanine |
| 3 | Leucine | 2.9 | 132.1 → 86.1 | 15 | 10 | 5,5,5-D3-leucine |
| 4 | Isoleucine | 3.1 | 132.1 → 86.1 | 15 | 10 | U-13C6,U-D10,15N-isoleucine |
| 5 | Allo-isoleucine | 3.1 | 132.1 → 86.1 | 15 | 10 | – |
| 6 | Methionine | 3.5 | 150.0 → 104.0 | 16 | 10 | methyl-D3-methionine |
| 7 | Homocysteine | 3.9 | 136.0 → 90.0 | 15 | 10 | D8-homocystine |
| 8 | Homocysteine-cysteine disulphide | 4.0 | 255.0 → 134.0 | 15 | 10 | D8-homocystine |
| 9 | Valine | 4.2 | 118.1 → 72.1 | 18 | 10 | 1-13C-valine |
| 10 | d-aminolevulinic acid | 4.2 | 132.0 → 86.0 | 15 | 15 | – |
| 11 | Proline | 4.3 | 116.0 → 70.1 | 20 | 10 | 2,3,3,4,4,5,5-D7-proline |
| 12 | Tyrosine | 4.4 | 182.1 → 136.1 | 20 | 15 | ring-D4-tyrosine |
| 13 | Pipecolic acid | 4.6 | 130.1 → 84.1 | 20 | 15 | D9-pipecolic acid |
| 14 | Taurine | 4.6 | 126.0 → 108.0 | 26 | 11 | 1,2-13C-taurine |
| 15 | Cysteine | 4.9 | 122.0 → 76.0 | 12 | 10 | – |
| 16 | Methionine-sulfone | 5.1 | 182.1 → 56.0 | 20 | 18 | methyl-D3-methionine |
| 17 | Alanine | 7.0 | 90.1 → 44.1 | 15 | 8 | 2,3,3,3-D4-alanine |
| 18 | Hydroxy-proline | 7.1 | 132.1 → 68.0 | 18 | 12 | U-13C4,U-D5,15N-threonine |
| 19 | Threonine | 7.7 | 120.0 → 74.1 | 15 | 10 | U-13C4,U-D5,15N-threonine |
| 20 | Glycine | 7.9 | 76.0 → 30.1 | 15 | 6 | 1,2-13C2-glycine |
| 21 | Methionine-sulfoxide | 8.4 | 166.0 → 74.0 | 15 | 14 | methyl-D3-methionine |
| 22 | Glutamine | 8.6 | 147.1 → 84.1 | 15 | 15 | 2,3,3,4,4-D5-glutamine |
| 23 | Serine | 8.6 | 106.0 → 60.0 | 15 | 10 | 3-13C-serine |
| 24 | Asparagine | 8.7 | 133.0 → 74.0 | 16 | 14 | 13C4-15N2-asparagine |
| 25 | Homocitrulline | 8.8 | 189.9 → 172.9 | 12 | 12 | 5-13C, 4,4,5,5-D4-citrulline |
| 26 | Citrulline | 9.0 | 176.1 → 159.0 | 15 | 10 | 5-13C, 4,4,5,5-D4-citrulline |
| 27 | Glutamic acid | 9.1 | 148.0 → 84.0 | 18 | 16 | 2,4,4-D3-glutamic acid |
| 28 | Aspartic acid | 9.9 | 134.0 → 74.0 | 15 | 15 | 2,3,3-D3-aspartic acid |
| 29 | Histidine | 10.3 | 156.1 → 110.0 | 15 | 15 | U-13C6-histidine |
| 30 | Arginine | 10.5 | 175.1 → 70.1 | 25 | 20 | guanido-15N2-arginine |
| 31 | Lysine | 10.8 | 147.1 → 84.1 | 20 | 15 | 4,4,5,5,-D4-lysine |
| 32 | Ornithine | 10.9 | 133.1 → 70.1 | 15 | 15 | 5,5-D2-ornithine |
| 33 | Homocystine | 10.9 | 269.0 → 136.0 | 15 | 10 | D8-homocystine |
| 34 | ASA-anhydrides | 11.0 | 273.2 → 70.2 | 25 | 25 | 5-13C, 4,4,5,5-D4-citrulline |
| 35 | Cystine | 11.9 | 240.9 → 74.0 | 20 | 20 | – |
| 36 | Argininosuccinic acid (ASA) | 12.1 | 291.2 → 70.2 | 25 | 25 | 5-13C, 4,4,5,5-D4-citrulline |