1992 Volume 39 Issue 11 Pages 1016-1022
Paper electrophoresis was examined for analysis of five 5'-ribonucleotides and the corresponding ribonucleosides as model compounds of food components. Paper electrophoreses were carried out at 700V/35cm for 1h on four types of Toyo Roshi filter paper with 0.1M boric acid-0.05M triethylamine buffer (pH 9.5) or 0.1M triethylammonium bicarbonate buffer (pH 7.5). The UV-absorbing spots on the electrophorogram were extracted with water and the UV absorption spectra were measured at pH 7.0. Correction of UV absorption on contaminants in filter paper itself was performed as follows: The real absorbance of the extract at the desired wavelength was obtained by subtracting the product of the correction factor and the absorbance measured at 320nm without nucleotidic absorption band from the measured absorbance. This factor was obtained as the ratio of absorbance of the extract of filter paper itself at the desired wavelength to that at 320nm. Recovery of a sample was estimated as the percentage of real maximum absorbance of the extract to that of original solution. This method gave reproducible recovery values of more than 92% for each sample from all the filter paper after electrophoresis. The percentages of respective components in total absorbance after separation by paper electrophoresis from the mixture solution of a 5'-nucleotide and the corresponding nucleoside were almost the same (errors were less than 1%) as those in the original mixture solution.
