Page 50 - Application Handbook - Liquid Chromatography

LAAN-A-LC-E277

Application Supercritical Fluid Extraction / Chromatography

News Analysis of Vitamin E in a Commercial Supplement

by Offline SFE-SFC-PDA
No.L501

Vitamin E, also called tocopherol, is a fat-soluble vitamin A HPLC pump with a low-pressure GE valve installed is
and an important chemical substance that exhibits an used in the solvent delivery system, and the extraction
antioxidant effect, particularly in the human body. There conditions can be optimized by changing the type of
are four tocopherols (α, β, γ and δ) that differ based modifier (maximum of four types, including eluent from
on the number and position of methyl groups. The α the trap column) and the concentration relative to
-tocopherol exhibits the strongest antioxidant activity, carbon dioxide. Extract is retained in the trap column,
and this is the tocopherol form found in most and the low-pressure GE valve on the solvent delivery
commercial supplements as vitamin E. Since it is highly pump is switched to the solvent suitable for elution
fat-soluble, a quick and simple extraction method using from the trap column. Then the eluent is collected in
supercritical fluid is expected to be applicable. In this test tubes with a fraction collector.
article, we introduce a procedure for α-tocopherol
pretreatment that uses supercritical fluid extraction (SFE).

n Offline SFE System n SFE Treatment for α-Tocopherol
While the online SFE-SFC system has already been The commercial supplement used as an actual sample
described in several Application News articles, many may be present as a paste inside the capsule and may
have expressed the desire to combine SFE with existing be moisture absorbent. As shown in Fig. 2, we mixed
analytical methods other than SFC, and SFE has gained 275 mg of paste supplement with 1 g of Miyazaki
attention for its flexibility in terms of sample handling. Hydro-Protect, which is a dehydrating agent for SFE
The advantages of SFE are as follows. sold by Shimadzu, and transferred this mixture to the
1. Quick and highly efficient extraction using supercritical SFE extraction vessel.
fluid that is highly permeable and has a high diffusion
rate.
2. Extraction of unstable compounds under mild
temperature conditions with light-shielding. 275 mg of content of commercial supplement
3. Low cost compared to solvent extraction.
4. Complete automation of the extraction procedure.
5. Easy handling of the extraction sample. Add 1 g of dehydrating agent
6. Compatible with various analysis methods. MIYAZAKI Hydro-Protect
Fig. 1 shows a flow diagram for an offline SFE system.
A supercritical state is present upstream of the BPR Mix well
back-pressure control unit. Valves inside the SFE unit are
controlled to switch between static extraction via
enclosure of supercritical fluid in the vessel and dynamic
extraction via passage of supercritical fluid through the Transfer to 5 mL of vessel
vessel, which enables quick and highly efficient
extraction of the target compounds. Fig. 2 Preliminary Pretreatment for Supplement Sample Before SFE

CO2 pump
SFE unit BPR Column oven Fraction collector
CO2
cylinder

Pump Trap column

Tube
Vessel
Modifier Elution solvent

Fig. 1 Flow Diagram of Supercritical Fluid Extraction (SFE) System