Spectroscopic characterisation and identification of ecdysteroids using high-performance liquid chromatography combined with on-line UV--diode array, FT-infrared and 1H-nuclear magnetic resonance spectroscopy and time of flight mass spectrometry.
A prototype multiply hyphenated reversed-phase HPLC system has been applied to the analysis of a mixture of pure ecdysteroids and an ecdysteroid-containing plant extract. Characterisation was achieved via a combination of diode array UV, 1H NMR, FT-IR spectroscopy and time of flight (TOF) mass spectrometry. This combination of spectrometers allowed the collection of UV, 1H NMR, IR and mass spectra for a mixture of pure standards enabling almost complete structural characterisation to be performed. The technique was then applied to a partially purified plant extract in which 20-hydroxyecdysone and polypodine B were identified despite incomplete chromatographic resolution and the presence of co-chromatographing interferents. The experimental difficulties in the use of such a systems for these analytes are described.
Louden
D
D
LGC, The Heath, Runcorn, Cheshire, UK.
Handley
A
A
Taylor
S
S
Lenz
E
E
Miller
S
S
Wilson
I D
ID
Sage
A
A
Lafont
R
R
D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D026461:Ecdysteroids; D012015:Reference Standards; D013057:Spectrum Analysis / Q000379:methods*; D013256:Steroids / Q000737:chemistry*
D026461:Ecdysteroids; D013256:Steroids