| Model | Ultimate 3000 (Thermo Scientific Dionex, Waltham, MA, USA) |
| Detector | 1. UV detector: 338 nm2. FL detectorExcitation: 340 nm, emission: 450 nm (OPA)Excitation: 266 nm, emission: 305 nm (FMOC) |
| Column | VDSpher 100 C 18-E (4.6×150 mm, 5 μm)(VDS optilab, Berlin, Germany) |
| Mobile phase | A: 20 mM sodium phosphate monobasic (pH 7.8)B: water/acetonitrile/methanol (10:45:45, v/v) |
| Gradient condition | Time (min)024.024.526.026.530.0 | %B05710010000 |
| Flow rate | 1.5 mL/min |
| Injection volume | 0.5 μL |
| Temperature | Column: 40°CSample: 20°C |