Column luna 5 μm c18 100

The HPLC–UV analysis of the flavones in the artichoke leaf extract was performed on an Agilent 1200 series HPLC system; HPLC conditions: column Luna 5 μm C18 100 Å, 250 × 4.6 mm (Phenomenex); column temperature: 40 °C; solvent system: A—H₂O/methanol/formic acid: 74.7/25/0.3 (v/v/v), B—acetonitrile/formic acid: 99.7/0.3 (v/v); gradient profile: isocratic 0% B for 8 min, 100% B over 30 min, isocratic 100% B for 6 min, 0% B over 4 min, isocratic 0% B for 6 min; flow rate: 0.5 mL/min; injection volume: 50 μL; sample concentration: 1 mg/mL in 50% methanol; UV-detection: λ = 270, 347 nm; internal standard: caffeine (10 μg/mL). LOD and LOQ were identified with LOD = 0.08 μg/mL and LOQ = 0.3 μg/mL.

Arbutin quantification in SFE was performed according to [65 (link)], with slight modifications, on an Agilent 1200 series HPLC system (Model G1312B) (Agilent Technologies, Santa Clara, CA, USA) equipped with a degasser (G1379B), binary pump (G1312B), auto-sampler (G1317C), column oven (G1316B) and DAD detector (G1315). The HPLC conditions: column Luna 5 μm C18 100 Å, 250 × 4.6 mm (Phenomenex, Torrance, CA, USA); solvent system: A—0.04% formic acid, B—methanol; gradient profile: isocratic 2% B for 3 min, 25% B over 1 min, isocratic 25% B for 4 min, 50% B over 5 min, 80% B over 10 min, isocratic 80% B for 7 min, 2% B over 2 min, isocratic 2% B for 5 min; flow rate: 0.6 mL/min; injection volume: 20 μL; sample concentration: 1 mg/mL in 50% methanol; UV-detection: λ = 280 nm; internal standard: caffeine (10 μg/mL). LOD and LOQ were identified with LOD = 0.1 μg/mL and LOQ = 0.5 μg/mL.