ペーパークロマトグラフィーに関する研究 (第1報)

Rf値の補正について

抄録

In order to examine reproducibility of Rf values in paper chromatography, the most common partition chromatography was carried out on Zaffaroni-type impregnated filter paper and two-componental solvent system. Following conclusions were made on the cause of variation in Rf values and the method of correcting it.
Seven factors were given as the cause of variation: (i) Temperature, (ii) characteristics of the filter paper, (iii) adsorption of filter paper, (iv) composition of the stationary phase and mobile phase, (v) volume ratio (Vs/Vm) of stationary phase and mobile phase in unit weight of the filter paper, (vi) atmospheric humidity, and (vii) uniform distribution of the stationary phase. It was found that this volume ratio, Vs/Vm, is the main factor of variation if the temperature is kept constant and could be taken as the standard of correction.
In order to calculate this volume ratio, rate of void space of the filter paper was considered and this was measured with three kinds of solvent. It was thereby found that the use of a solvent with different degree of swelling filter paper fiber gave different rate of void space.
Effect of humidity on impregnated paper was observed through weight variation and it was found that it is necessary to carry out drying procedure in high humidity and that impregnation in a solvent containing water (including reversed-phase chromatography) made it impossible to obtain constant Rf values.
In order to have the filter paper retain the stationary phase uniformly, it was necessary to soak the filter paper in the solution horizontally for 10-20 minutes and treated rapidly in horizontal position.
Correction formula (equation (5)) for Rf values was established and the value was converted to Rfu value (Rf value where Vs/Vm=1/2) by interpolation of the calculated values for Vs/Vm. Since this is a small value of variation, this correction formula was considered to be appropriate in the range where adsorption can be neglected. According to this formula, it is possible to calculate the Rf value in accordance with variation in Vs/Vm on the basis of Rfu value and to remove the difference in filter papers with different rate of void space. Further, it is considered that this formula is applicable to non-impregnated paper.