RESUMO
The gas chromatograph (GC)-infrared spectroscopy (IR) technique combines the particular separating capacity of GC and the faultlessly with distinguishing capacity of molecular structure of IR, its detective sensitivity is very high and itis used to separate and identify many kinds of complicated compounds from element speciation analysis, natural products, and gasoline. This paper introduces the principle of GC-IR. Three types of interface techniques, light pipe technique, matrix isolation technique and direct deposition technique are compared. Connection type with other detections and factors influencing sensitivity in interface are also introduced. The improvement and achievement in coupling GC system, interface, data processing techniques and its application is reviewed in the present paper.
Assuntos
Cromatografia Gasosa , Espectrofotometria Infravermelho , Produtos Biológicos/análise , GasolinaRESUMO
Quality control issues overshadow potential health benefits of the edible mushroom Flammulina velutipes, with the detection and isolation of polysaccharides posing particular problems. In this study, multiple-fingerprint analysis was performed using chemometrics to assess polysaccharide quality and antioxidant activity of F. velutipes fruiting bodies from different sources. The authentic source exhibited differences in both oxygen radical absorbance capacity and ferric reducing antioxidant power from foreign sources. IR spectroscopic/HPLC fingerprints of polysaccharide extracts from the authentic source were established and applied to assess the polysaccharide quality of foreign sources. Analysis of IR fingerprints using Pearson correlation coefficient gave correlation coefficient r values of 0.788 and 0.828 for two foreign sources, respectively, indicating distinctness from the authentic source. Analysis of HPLC fingerprints using the supervised method by Traditional Chinese Medicine could not discriminate between sources (r > 0.9), but principal component analysis of IR and HPLC fingerprints distinguished the foreign sources.