Determination of Vitamins D₂ and D₃ in Edible Fungus by Reversed-Phase Two-Dimensional Liquid Chromatography

Table 1

The parameters of two-dimensional chromatography.

	First dimension	Second dimension
Flow rate	0.4 mL/min	0.4 mL/min
Mobile phase A	H2O	ACN:H2O = 95:25
Mobile phase B	MeOH:ACN = 25:75	MeOH
Autosampler	50 µL
Column	Daicel chiralcel, OD-3R, 2.1 mm × 150 mm, 3 µm	Agilent ZORBAX Eclipse PAH, 4.6 × 100 mm, 3.5 µm
Column temperature	35°C	35°C
Detector	UV 264 nm	PDA 264 nm
Valve	0 to 15.3 minutes: Position 1–2 (phase 1); 15.3 to 17.2 minutes: Position 1–6 (phase 2); 17.2 to 40 minutes: Position 1–2 (phase 3)
Capture column	Agilent ZORBAX Extend-C18, 4.6 × 12.5 mm, 5 µm