Application Notes
Analysis of Ephedra Alkaloids by GC
Derivatized alkaloid compounds in banned herbal supplement Ephedra separated by capillary GC/FID in 4 minutes.
Analysis of Ephedra Alkaloids by Gas Chromatography with an Alltech AT-5ms Capillary Column, Alltech Application Note #A0041, April 28, 2004.
The alkaloid components of the banned herbal supplement Ephedra were separated using capillary gas chromatography with flame ionization detection (FID) after derivatization of the alkaloids with N-Methyl-N-trimethylsilyltrifluoroacetamide (MSTFA). The derivatization allowed the separation of the diastereoisomers without the use of a chiral stationary phase.
The derivatized form of 5 drugs found in Ephedra and one used as an Epehdra substitute were separated on an Alltech Heliflex AT-5ms capillary column, 30m x 0.25mm x 0.25µm (Part No. 15807) and the components analyzed using a flame ionization detector at 310°C. The oven temperature was initially held at 150°C for 2 minutes and raised to 230°C at 10°C/min with a final 2-minute hold. The injector temperature was 250°C, the carrier gas was helium and around 10ng were injected on column.
The derivatized form of the Ephedra alkaloids methylephedrine, norpseudoephedrine, norephedrine, ephedrine, pseudoephedrine and the Ephedra substitute synephrine were baseline separated in less than 10 minutes using these conditions.
Key Analyte(s)
Ephedra
ephedrineephedrine (L-ephedrine) is a drug obtained from the extract of the Ma Huang herb commonly known as Ephedra. It has been used to treat asthma and is a banned weight loss ingredient in dietary supplements. It is most often measured using HPLC, GC/FID and G
methylephedrine
norephedrine
norpseudoephedrine
synephrine
Equipment
Alltech Heliflex® AT-5ms Capillary ColumnsAlltech Heliflex® AT-5ms capillary columns are a line of non-polar fused silica GC columns manufactured and sold by Alltech Associates. They are specifically designed for use with mass spectrometers.
Technique
GC/FIDIn GC/FID, the FID or flame ionization detector detects analytes by measuring an electrical current generated by electrons from burning carbon particles in the sample.
Source
Alltech Associates, Inc.Alltech Associates, Inc., one of the leading suppliers of HPLC columns, manufactures and distributes HPLC, GC and IC columns, accessories and consumables and maintains a large searchable database of application notes and chromatograms on its website.
