. 2025 Nov 6;15(51):43293–43303. doi: 10.1039/d5ra06441d

Table 3. Selectivity and sensitivity of reagents employed for the spectrophotometric measurement of zinc.

Reagent	λ _max (nm)	ε, L mol⁻¹ cm⁻¹	LOD μg mL⁻¹	Interference	Ref.
1-(2-Thiazolylazo)-2-naphthol	590	2.02 × 105	2.02	Cu²⁺, Co²⁺ and Ni²⁺	39
1,3-Cyclohexanedionedithiosemicarbazone	570	1.10 × 104	1.42	Fe³⁺, Al³⁺, Ni²⁺, Cu²⁺ and Pb²⁺	40
1-(2-Pyridylazo)-2-naphthol	560	—	7.30	Fe²⁺ and Fe³⁺	41
2-(2-Quinolylazo)-5-dimthylaminophenol	590	—	1.22	—	42
Glyoxaldithiosemicarbazone	433	1.42 × 104	1.30	Bi³⁺, Cd²⁺, Ni²⁺, IO³⁻ and BrO³⁻	43
N-Ethyl-3-carbazolecarboxaldehyde-3-thiosemicarbazone	420	1.55 × 104	1.55	Pb²⁺, Ni²⁺, Pd²⁺, Cu²⁺, and Cd²⁺	44
2-(4-Pyridylazo)resorcinol (500 mL)	500		94.0	Pb²⁺, Mn²⁺, Cu²⁺, Cd²⁺, V⁵⁺, Ni²⁺ and Co²⁺	45
Xylenolorangeandcetylpyridiumchloride	580	2.10 × 104	1.11	Cd²⁺, Hg²⁺, Cu²⁺, Bi³⁺, Pd²⁺, Ni²⁺, Co²⁺ and Ag⁺	46
Zincon (1000 mL)	621	—	31.0	Co²⁺, Cu²⁺, Cd²⁺, Bi³⁺, Pb²⁺, Hg²⁺, Al³⁺ and Cr³⁺	47
Nitrilotriacetic acid	550	—	33.0	Fe²⁺, Co²⁺, Fe³⁺ and Al³⁺	48
5-(2-Benzothiazolylazo)-8-hydroxyquinoline (1000 mL)	675	2.50 × 107	6.28	Cu²⁺, Cd²⁺ and Ni²⁺	49
1-(2-Pyridylazo)-2-naphthol (2000 μL)	555		50.0	Mn²⁺, Fe³⁺, Cu²⁺ and Mo⁶⁺	50
1-(2-Tiazolylazo)-2-naphthol	595		25.0	Cu²⁺, Ni²⁺, Pb²⁺ and Sn²⁺	51
AHDDO (500 mL)	640	3.91 × 107	0.15	Cd²⁺ and Cu²⁺	This work
AHDDO (1000 mL)	640	9.78 × 107	0.006	Cd²⁺ and Cu²⁺	This work