HPLC, using superheated D20 as the mobile phase, combined with on-line characterization via a combination of diode array UV, 1H NMR, FT-IR spectroscopy, and mass spectrometry has been used for the analysis of a standard of 20-hydroxyecdysone- and ecdysteroid-containing plant extracts. This combination of spectrometers enabled the on-flow collection of UV, 1H NMR, IR, and mass spectra not only for pure 20-hydroxyecdysone (100-400 microg on column) but also the major ecdysteroids present in crude extracts of Silene otites, Silene nutans, and Silene frivaldiskyana. The ecdysteroids unequivocally identified in these extracts included 20-hydroxyecdysone, polypodine B, and integristerone A.
The reversed-phase chromatography of a number of model pharmaceuticals using deuterium oxide (D 2 O) as the mobile phase at elevated temperatures, including superheated conditions (greater than 100 °C), is described. Following elution the analytes were characterised on-line via a combination of diode array UV, 1 H-NMR, FT-IR spectroscopy and mass spectrometry. This combination of spectrometers enabled the on-flow collection of full UV, 1 H-NMR, IR and mass spectra for a range of compounds in amounts ranging from 46 to 500 mg on-column. The advantages of the use of D 2 O alone as mobile phase for chromatography with multiple spectroscopic characterisation of analytes is discussed.
A prototype multiply hyphenated system has been applied to the analysis of a mixture of nonsteroidal antiinflammatory drugs separated by reversed-phase HPLC. Characterization of the model NSAIDs was achieved via a combination of diode array UV, 1H NMR, FT-IR spectroscopy, and time-of-flight mass spectrometry. This combination of spectrometers allowed the collection of UV, 1H NMR, IR, and mass spectra together with atomic composition data enabling almost complete structural characterization to be performed.
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