Summary
This experiment follows the method specified in GB 5413.9-2020 to saponify the samples and then extract them using a TUP VD SPE column, which provides a simple, fast, and efficient extraction process. The TUP VD SPE column reduce impurity contamination, and the procedure is easy to perform.
The Procedure
Reagents and Materials:
- Petroleum ether， Methanol ，n-Hexane
- Solid-phase extraction column: TUP VD solid-phase extraction column, 20g/60ml (TUP part number: E76-2060)
Saponification of Samples
- Reference to GB 5413.9-2020.
Separation and Purification of Vitamins
- Sample Loading: Transfer the entire saponification samples into the TUP VD SPE column and let it stand for 15 minutes.
- Elution: Add 80ml of petroleum ether in two portions for elution. Collect the eluate using a round-bottom flask.
- Concentration: Place the eluate （in the round-bottom flask） on a rotary evaporator and evaporate it at 40°C±2°C under nitrogen atmosphere until nearly dry (avoid complete dryness). Transfer the residue to a 10ml volumetric flask and make up to the mark with petroleum ether.
- Sample Dissolution: Accurately transfer 2.0ml of the solution from the aforementioned flask to Bottle A, and then accurately transfer 7.0ml of the solution to Bottle B. Dry the solutions under nitrogen gas at 40°C. To Bottle A, add 5.0ml of methanol and dissolve the contents by vortexing. To Bottle B, add 2.0ml of n-hexane and dissolve the contents by vortexing. Filter the solutions of A and B using a syringe filter and transfer them to 1.5ml sample vials for analysis.
Note: Bottle A is used for testing vitamins A and E, while Bottle B is used for testing vitamin D.