Ion-Selective Electrode for Anionic Surfactants Using Hexadecyl Trimethyl Ammonium Bromide-Sodium Dodecylsulfate as an Active Ionophore

Table 1

Response characteristics of the anionic surfactant-selective electrode based on PVC membrane to SDS with different composition.

Membrane^a	Slope (mV/decade)	Linear range (mol L^−1)	Detection limit (mol L^−1)	Correlation coefficient (𝑟)
1	−50.7 ± 1.2	7.5 × 10^−6 to 2.5 × 10^−3	4.6 × 10^−6	0.9972 ± 0.0004
2	−58.0 ± 0.9	5.0 × 10^−6 to 2.5 × 10^−3	2.9 × 10^−6	0.9987 ± 0.0003
3	−65.5 ± 2.4	7.5 × 10^−6 to 2.5 × 10^−3	5.9 × 10^−6	0.9935 ± 0.0007

^aIngredients of membrane (wt%): (1) DOP (60%), PVC (34%), ion pair (1%), (2) DOP (60%), PVC (33%), ion pair (2%), (3) DOP (60%), PVC (32%), ion pair (3%).