A new route to select the referable values of property indicators for normalization and its application in screening polymeric membrane heavy metal (Co, Ni, and Cr)-ion-selective electrodes with multiple high-response performances.

Abstract

Distance to target normalization may not be suitable to select the referable values, (RC)refer, and responsive characteristic (RC) indicators, for the electrode comprehensive quality index (IECQ). (RC)refer is selected as an excellent response property value in alliance with corresponding constants (e.g., 1.8 or 2.5) in this method. It is recently found that these constants are not appropriate to normalize indicators for other ion-selective electrodes (ISEs). The present study aimed to report a new and universal route to select good (RC)refer values for the normalization without additional constants by only controlling the mean value ([Formula: see text]) being 0.90 < [Formula: see text] < 1.1. The route provided reliable results of both (RC)refer for indicator normalization and IECQ values. It has been successfully applied to select the referable values (RC)refer of each indicator for the IECQ of three heavy metal (HM) (Co, Ni, and Cr)-ISEs. The second aim of the work is to screen these heavy metal-ion-selective electrodes (HM-ISEs) with highly multiple response properties by using the IECQ. Twenty-four HM-ISEs with the top 3 IECQ values have been recommended. For example, the largest IECQ for three indicators, [Formula: see text], PS, and PRT, which was used as the main indicator (MI), was 1.461 for Co2+-ISE, 1.385 for Ni2+-ISE, and 1.561 for Cr3+-ISE, respectively. The results will be beneficial to meeting the special requirements to monitor/analyze HM ions in different water samples.