PRACTICAL APPLICABILITY OF SILICONE-RUBBER MEMBRANE SODIUM-SELECTIVE ELECTRODE BASED ON OLIGOSILOXANE-MODIFIED CALIX[4]ARENE NEUTRAL CARRIER

Silicone rubber-based Na+-sensing membranes, which do not require any special plasticizer and are therefore quite resistant to membrane dete rioration, can be practically applied to Na+-selective electrodes, as far as the neutral carrier is highly dispersible in silicone rubber. T he silicone rubber membrane Na+-selective electrodes based on an oligo siloxane-modified calix[4]arene neutral carrier are reliable for sodiu m assays in human body fluids such as blood sera and urine. Two other Na+ neutral carriers that are excellent ones for plasticized poly(viny l chloride) membranes did not give good results for silicone rubber me mbranes of the ion-selective electrodes, due to their poor dispersibil ity in silicone rubber.