The unretained peaks on the chromatogram represent material excluded from the column, either on the basis of molecular size or polarity (Bailey et al., 1996). The retention times of the unretained peaks, for both the aqueous and ethanolic solutions, are less than 5 min with a stronger absorbance at 360 nm, or yellow in colour, than at 460 nm, or brown in colour. Similar results for a chromatogram of pH 5.0 aqueous glucose/glycine solution had been reported previously by Bailey et al. (1996).
Both the convex broad band and tailing broad band are unresolved bands. Snyder, Stadalius, and Quarry (1983) suggested that these bands be designated as unresolvable polymers. There is no tailing broad band in the chromatogram of either ethanolic or aqueous solution in the present study. A convex broad band appears in the 460 nm spectra (Figs. 1C and 2C), suggesting the existence of melanoidin polymer in both of the browned aqueous and ethanolic G–G solutions. Bailey et al. (1996) reported neither convex broad bands nor tailing broad bands in the chromatogram of heated pH 5.0 aqueous glucose/glycine (1 M/1 M) solution. Monti, Bailey, and Ames (1998) reported the occurrence of tailing broad bands in the chromatogram of heated aqueous glucose/glycine (1 M/1 M) solution without pH buffer. The discrepancy in the presence of broad band between our observation and the above-mentioned reports could be attributed to the difference in the pH of reaction mixture and the heating time–temperature history.
The unretained peaks on the chromatogram represent material excluded from the column, either on the basis of molecular size or polarity (Bailey et al., 1996). The retention times of the unretained peaks, for both the aqueous and ethanolic solutions, are less than 5 min with a stronger absorbance at 360 nm, or yellow in colour, than at 460 nm, or brown in colour. Similar results for a chromatogram of pH 5.0 aqueous glucose/glycine solution had been reported previously by Bailey et al. (1996).Both the convex broad band and tailing broad band are unresolved bands. Snyder, Stadalius, and Quarry (1983) suggested that these bands be designated as unresolvable polymers. There is no tailing broad band in the chromatogram of either ethanolic or aqueous solution in the present study. A convex broad band appears in the 460 nm spectra (Figs. 1C and 2C), suggesting the existence of melanoidin polymer in both of the browned aqueous and ethanolic G–G solutions. Bailey et al. (1996) reported neither convex broad bands nor tailing broad bands in the chromatogram of heated pH 5.0 aqueous glucose/glycine (1 M/1 M) solution. Monti, Bailey, and Ames (1998) reported the occurrence of tailing broad bands in the chromatogram of heated aqueous glucose/glycine (1 M/1 M) solution without pH buffer. The discrepancy in the presence of broad band between our observation and the above-mentioned reports could be attributed to the difference in the pH of reaction mixture and the heating time–temperature history.
การแปล กรุณารอสักครู่..
