Figures (3)  Tables (2)

    • Figure 1. 

      Response slopes, detection limits, and selectivity coefficients for porphyrin-based ionophores. (a) Response slopes (left axis) and detection limits (right axis). (b) Selectivity coefficients logKijSSM of porphyrin-based ionophores with different substituents. (c) Selectivity coefficients logKijSSM of porphyrin-based ionophores with different coordinated metal ions.

    • Figure 2. 

      Response slopes, detection limits, and selectivity coefficients for ionic additives at varying additive-to-ionophore ratios. (a) Response slopes (left axis) and detection limits (right axis) of various ionic additives at 1:2, 1:1, 2:1 additive-to-ionophore ratios. (b) Selectivity coefficients logKijSSM of ionic additives at a 1:2 additive-to-ionophore ratio against various interfering ions. (c) Selectivity coefficients logKijSSM of ionic additives at a 1:1 additive-to-ionophore ratio against various interfering ions. (d) Selectivity coefficients logKijSSM of ionic additives at a 2:1 additive-to-ionophore ratio against various interfering ions.

    • Figure 3. 

      Evaluation performance of the proposed ISE. (a) Dynamic response time of optimal electrode for step changes in concentration of ClO4− (low to high), inset graph represents the linear region of the average values obtained over the 2- to 10-min interval. (b) Effect of pH of test solutions on the response of the proposed optimized electrode: 10−4–10−1 M NaClO4·H2O. (c) Evaluation of ion-selective electrode accuracy in real wastewater samples.

    • Category Ionophores Plasticizers Ionic additives PVC / plasticizers / ionophores / ionic additives (mg)a Evaluation test
      I Fe(III)TPPCl NPOE CTAB 600 :1200 : 20 : 60 Linearity, Sensitivity and Selectivity Coefficient
      Fe(III)TMPPCl 600 : 1200 : 20 : 60
      Fe(III)TClPPCl 600 : 1200 : 20 : 60
      Co(II)TPP 600 : 1200 : 20 : 60
      Cu(II)TPP 600 : 1200 : 20 : 60
      Mn(III)TPPCl 600 : 1200 : 20 : 60
      Zn(II)TPP 600 : 1200 : 20 : 60
      II Fe(III)TPPCl DOS CTAB 600 : 600 : 20 : 60 Linearity and Sensitivity
      600 : 900 : 20 : 60
      600 : 1200 : 20 : 60
      600 : 1500 : 20 : 60
      DOP 600 : 600 : 20 : 60
      600 : 900 : 20 : 60
      600 : 1200 : 20 : 60
      600 : 1500 : 20 : 60
      DBP 600 : 600 : 20 : 60
      600 : 900 : 20 : 60
      600 : 1200 : 20 : 60
      600 : 1500 : 20 : 60
      NPOE 600 : 600 : 20 : 60
      600 : 900 : 20 : 60
      600 : 1200 : 20 : 60
      600 : 1500 : 20 : 60
      III Fe(III)TPPCl NPOE TDMACl 600 : 1200 : 20 : 10 Linearity, Sensitivity and Selectivity Coefficient
      600 : 1200 : 20 : 20
      600 : 1200 : 20 : 40
      CTAB 600 : 1200 : 20 : 10
      600 : 1200 : 20 : 20
      600 : 1200 : 20 : 40
      MTOACl 600 : 1200 : 20 : 10
      600 : 1200 : 20 : 20
      600 : 1200 : 20 : 40
      a Add the components to 5 mL of THF in the listed proportions.

      Table 1. 

      Optimization of PVC-based membrane sensors with varied plasticizers and ionophores: comparative evaluation of sensitivity, linearity, and selectivity for metal-based porphyrin derivatives detection

    • No. Composition (mg) Slope (mV·decade−1) Linear range (M) LOD (M)
      PVC Plasticizers Ionophores Ionic additives
      1 600 DOS, 600 Fe(III)TPPCl, 20 CTAB, 60 −46.33 10−4 ~ 10−1 10−4.07
      DOS, 900 −39.89 10−5 ~ 10−1 10−5.17
      DOS, 1200 −47.78 10−5 ~ 10−1 10−5.07
      DOS, 1500 −40.48 10−5 ~ 10−1 10−4.95
      2 600 DOP, 600 Fe(III)TPPCl, 20 CTAB, 60 −31.65 10−4 ~ 10−1 10−3.99
      DOP, 900 −35.48 10−4 ~ 10−1 10−3.9
      DOP, 1200 −39.05 10−5 ~ 10−1 10−5.04
      DOP, 1500 −35.15 10−5 ~ 10−1 10−4.95
      3 600 DBP, 600 Fe(III)TPPCl, 20 CTAB, 60 −40.66 10−4 ~ 10−1 10−4.01
      DBP, 900 −43.09 10−5 ~ 10−1 10−5.21
      DBP, 1200 −50.83 10−5 ~ 10−1 10−4.99
      DBP, 1500 −55.09 10−5 ~ 10−1 10−5.1
      4 600 NPOE, 600 Fe(III)TPPCl, 20 CTAB, 60 −50.92 10−3 ~ 10−1 10−3.17
      NPOE, 900 −57.08 10−3 ~ 10−1 10−3.47
      NPOE, 1200 −44.03 10−7/10−6 ~ 10−1 10−6.53
      NPOE, 1500 −59.19 10−4 ~ 10−1 10−4.3

      Table 2. 

      Composition of membranes and potentiometric response characteristics of perchlorate-selective electrodes based on Fe(III)TPPCl