RESUMO
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.
Assuntos
Análise de Injeção de Fluxo/métodos , Análise Espectral/métodos , Ácido 4-Aminobenzoico/análise , Análise de Injeção de Fluxo/instrumentação , Espectroscopia de Ressonância Magnética/métodos , Espectrometria de Massas/métodos , Espectrofotometria Infravermelho/métodos , Espectrofotometria Ultravioleta/métodos , Espectroscopia de Infravermelho com Transformada de Fourier , Análise Espectral/instrumentaçãoRESUMO
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.
Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Polímeros/análise , Usos Especializados de Substâncias Químicas/análise , Hidroxitolueno Butilado/análogos & derivados , Hidroxitolueno Butilado/análise , Cresóis/análise , Espectroscopia de Ressonância Magnética/métodos , Espectrometria de Massas/métodos , Sistemas On-Line , Polímeros/química , Sensibilidade e Especificidade , Usos Especializados de Substâncias Químicas/isolamento & purificação , Espectrofotometria/métodos , Espectrofotometria Infravermelho/métodosRESUMO
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.