Table 6.
Performance comparison of different methods for the determination of Phe and/or tyr.
| Amino acid (s) | Technique | LOD | Ref |
|---|---|---|---|
| Phe | Spectrophotometry | 31.6 µmol l− 1 | 26 |
| Tyr andTrp | HPLC-FLD | 0.014 µmol l− 1 for Tyr | 27 |
| Phe and Tyr | HPLC-FLD | 0.3 µmol l− 1 for Phe and Tyr | 28 |
| Trp and Tyr with their metabolites | HPLC-ESI-MS | 60.0 nmol l− 1 for Tyr | 29 |
| Tyr | Differential pulse voltammetry | 2.7 nmol l− 1 | 30 |
| Phe | Differential pulse voltammetry | 47.0 nmol l− 1 | 31 |
| Phe and Tyr | HPTLC | 17.37 µmol l− 1 for Phe and 6.35 µmol l− 1 for Tyr. | This work |