RESUMEN
The reversed-phase chromatography of a number of polymer additives has been undertaken with on-line characterisation via a combination of diode array UV, (1)H NMR, 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 common polymer additives in amounts ranging from ca. 230 to 900 micro g on-column. The practical difficulties associated with multiple hyphenation and potential future developments are discussed.
Asunto(s)
Cromatografía Líquida de Alta Presión/métodos , Polímeros/análisis , Usos Especializados de Sustancias Químicas/análisis , Hidroxitolueno Butilado/análogos & derivados , Hidroxitolueno Butilado/análisis , Cresoles/análisis , Espectroscopía de Resonancia Magnética/métodos , Espectrometría de Masas/métodos , Sistemas en Línea , Polímeros/química , Sensibilidad y Especificidad , Usos Especializados de Sustancias Químicas/aislamiento & purificación , Espectrofotometría/métodos , Espectrofotometría Infrarroja/métodosRESUMEN
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.
Asunto(s)
Ecdisteroides/análisis , Extractos Vegetales/análisis , Animales , Cromatografía Líquida de Alta Presión/instrumentación , Cromatografía Líquida de Alta Presión/métodos , Óxido de Deuterio , Diseño de Equipo , Calor , Análisis EspectralRESUMEN
Studies on the capabilities of flow injection analysis (FIA) combined with on-line characterisation of model compounds via a combination of diode array UV, 1H-NMR, FT-IR spectroscopy and mass spectrometry are described. Using this combination of spectrometers enabled the on-flow collection of UV, 1H-NMR, IR and MS for a range of model compounds. Samples were introduced into the system as solutions in deuterium oxide in concentrations ranging from 1.4 to 8.4 mg ml(-1). A sample volume of 100 microl was used for FIA at a flow rate of 1 ml min(-1). From these studies a practical working quantity of ca. 140 microg/sample of analyte was determined which provided characteristic spectra.