Effect of the PVC membrane composition on the performance characteristics of the prepared sensors^b.

Sensor	Composition		Performance
	Plasticizer	Ion exchanger	Linearity range (M)	Slopea (mV per decade)	r a
1	TCP	TPB	1.58 × 10−5 to 3.85 × 10−3	34.92	0.9713
2	TCP	PM	1.58 × 10−5 to 3.85 × 10−3	30.96	0.9907
3	TCP	AR	1.58 × 10−5 to 3.85 × 10−3	49.83	0.9879
4	TCP	PT	1.58 × 10−5 to 1.00 × 10−2	57.67	0.9965
5	DBP	PT	4.75 × 10−5 to 3.85 × 10−3	35.42	0.9793
6	DOP	PT	5.87 × 10−7 to 1.28 × 10−3	15.95	0.9918
7	NPPE	PT	5.87 × 10−7 to 4.28 × 10−4	10.56	0.9921
8	NPOE	PT	1.96 × 10−7 to 3.85 × 10−3	4.34	0.9339

^aAverage of three determinations.

^bTricresyl phosphate (TCP), tungstophosphoric acid hydrate (PT), sodium tetraphenyl borate (TPB), 12-molybdophosphoric acid (PM), ammonium reineckate (AR), dibutyl phthalate (DBP), dioctyl phthalate (DOP), 2-nitrophenyl phenyl ether (NPPE), 2-nitrophenyl octyl ether (NPOE).