Comparison of the proposed DTZ ion-selective method with published methods.

Method	Linear range (mol L−1)	Detection limit (mol L−1)	Response time (s)	Applications	Reference
HPTLC	8.8 × 10−8 to 8.8 × 10−7	4.4 × 10−8	—	Bulk drug and pharmaceuticals	5
Spectrophotometric	—	1.10 × 10−4	—	Commercial tablets and capsules	6
Cyclic voltammetry	2.0 × 10−6 to 8.0 × 10−5	7.0 × 10−8	—	Pharmaceutical formulation (capsule) and urine	8
PVC membrane	1.0 × 10−5 to 1.0 × 10−1	7.09 × 10−6	12	Pharmaceutical formulation and urine	10
DTZ-CPS	1.0 × 10−6 to 1.0 × 10−2	5.0 × 10−7	10	Urine and industrial water	P.W.a

^aP.W.: present work.