導電率法による水溶液中の非電解質濃度測定法の研究 Ｉ 基礎的検討と濃度計の試作:I. 基礎的検討と濃度計の試作 [in Japanese] Determination of nonelectrolytes in aqueous solution by conductivity measurement. I. Principle and construction of automatic analyzer.:I. Principle and construction of automatic analyzer [in Japanese]
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The electric conductivity of electrolyte in ethanol solution is very low compared with that in water, and in ethanol-water solvent it has an intermediate value. The authors observed that the ethanol-water mixture became more conductive by adding an electrolyte, KCl in this case, with conductivity increase bearing a linear relation to the amount of added salt, and further observed that the higher the ethanol/water ratio, the smaller the conductivity increase coefficient. Other several nonelectrolytes show similar behavior. This suggests that the nonelectrolyte in solution can be simply determined by measuring the conductivity difference before and after the addition of a salt, and this method is applicable to conductive samples. An automatic noneletrolyte analyzer has been constructed, based on the principle above mentioned. The analyzer is microprocessor-based with a digital display. By using this analyzer the concentration of ethanol, ethylene glycol, glycerin, acetone, dimethylformamide, glucose, fructose, maltose and sucrose in aqueous solution were measured. The reproducibility was tested on the measurements of 16.0% ethanol in aqueous solution; the results were <I>x</I>=16.05, <I>R</I>=0.3, σ<SUB>x</SUB> =0.089, R.S.D. =0.55 (<I>n</I> = 22). Errors in measurements of the samples, concentration range of 135%, did not exceed ± 0.3% (absolute value) except one.
- BUNSEKI KAGAKU
BUNSEKI KAGAKU 36(8), 473-478, 1987
The Japan Society for Analytical Chemistry