抄録
A chloride ion-selective solvent polymeric membrane electrode (Cl-ISE) using quaternary ammonium salts for determination of the ethanol concentration during sake fermentation is described. The ethanol response by a Cl-ISE is based on the change in the transfer activity coefficient of Cl- from water to ethanol. The logarithm value of the transfer activity coefficient increases linearly with increasing ethanol concentration. The Cl-ISE using a mixture of o-nitro-phenyloctyl ether and n-tetradecylalcohol as plasticizers and tetradodecylammonium salts as sensing materials showed good linearities for ethanol (−2.39 mV/%) and for Cl- (−53.6 mV/decade). Furthermore, the interference from co-existent components in sake mash with the response of the Cl-ISE was improved in comparison with that using other plasticizers and sensing materials. The Cl-ISE was found to show good accuracy in the measurement of ethanol in sake mash.
