Table 3.

Analytical parameters of reviewed research papers about the speciation and determination of mercury by electrochemical instruments.

S. number	Analyte	Analytical instrument used for the detection	Method	Limit of detection (LOD)#	Linearity range	Analyzed samples	Interference study	Supporting media	Reference
1	Hg(II)	DP-ASV	Electrochemical	4.99 × 10−8 M	—	Ambient water, tap, and wastewaters	Palladium-natural phosphate-carbon paste electrode enhances the selectivity for Hg2+	Natural phosphate electrodes	[103]
2	Hg(II)	SW-ASV	Electrochemical	0.04 × 10−6 M	0.2–10.0 μM	Foodstuffs	Simultaneously both Cd2+ and Hg2+ are determined and 1,000-fold for K+, Na+, Li+, NH4 +, Ca2+, Mg2+, Pb2+, Zn2+, Cr3+, Fe2+, Co2+, and Al3+ did not interfere	Carbon paste electrode	[104]
3	Hg(II)	Differential pulse voltammeter	Electrochemical	4.48 × 10−10 M	0.2–10 μg L−1	Spiked fish and plant samples	Cu(II), Mg(II), As(III), and Cr(II) were possible interferers	4,4′-Bipyridine-silver polymer	[105]
4	Hg(II)	Cyclic voltammeter	Electrochemical	0.8 × 10−14 M	10−14–10−7 M	—	Cu2+, Pb2+, Ni2+, Zn2+, Cr3+, Co3+, As5+, Fe2+, and Fe3+ did not interfere	Gold atomic cluster-chitosan	[106]
5	Hg(II)	Voltammeter (cyclic and differential pulse)	Biosensor	3.93 × 10−12 M	0.005–0.034 mM	Water samples	The working potential controlled to minimize the interference of other metal ions in test medium	PANI and PANI-co-PDTDA polymer films	[107]
6	Hg(II)	ASV	Electrochemical	4.98 × 10−9 M	4–160 ppb	Aquatic solutions	—	Glassy carbon electrode	[108]
7	Hg(II)	SW-ASV	Electrochemical	9.2 × 10−5 M	0.1–150.0 nM	Soil, gasoline, fish, tap, and wastewaters	400-fold mass ratio of Cu2+, Mn2+, Zn2+, Cr3+, Cr6+, Fe3+, Fe2+, Ni2+, and Co2+ did not interfere in the simultaneous determination of Cd2+, Pb2+, and Hg2+	Triphenyl phosphine	[109]
8	Hg(II)	Potentiometer	Electrochemical	9.77 × 10−6 M (PME)1 7.76 × 10−7 M (CGE)1	1.0 × 10−1–5.0 × 10−6 M (PME)  1.0 × 10−1–5.0 × 10−7 M (CGE)	Water samples	Ag+ has small interference in the determination of Hg2+	1,3-Alternate thiacalix[4]crown	[110]
9	Hg(II)	Potentiometer	Electrochemical	1.0 × 10−8 M	5.0 × 10−8–1.0 × 10−2 M	—	The selectivity coefficient of the other ions is ranging from 2.9 to 4.9	PVC membrane	[111]
10	Hg(II)	DPSV	Electrochemical	0.05 × 10−12 M	1–500 nM	Water samples	Pb2+, Th3+, Cu2+, Cd2+, Ni2+, and Al3+ did not interfere	Gold nanoparticles	[112]
11	Hg(II)	SW-ASV	Ultrasonic extraction	—	—	Indoor dust samples	—	Gold nanoparticles	[113]
12	Hg(II)	Cyclic voltammeter	Electrochemical	1.9 × 10−9 M	40–170 μg L−1	Wastewaters	—	Biotinyl Somatostatin-14 peptide	[114]
13	Hg(II)	Potentiometer	Electrochemical	3 × 10−6 M	5 × 10−6–1 × 10−2 M	Contaminated water	Na+, K+, Mg2+, Ca2+, Zn2+, Cu2+, Cr3+, Fe3+, and Pb2+ did not interfere in the determination of Hg2+	Dithizone and di-n-butyl phthalate	[115]
14	Hg(II)	DP-ASV	Electrochemical	0.483 × 10−6 M	300–700 ng mL−1	—	No interference of Cd, Ni, Zn, and Cu in 50-, 25-, 100-, and 5-fold in excess, respectively	Nanocellulosic fibers	[116]
15	Hg(II)	—	Electrochemical	0.5 × 10−9 M	1.0 nM–1.0 μM		Zn2+, Mg2+, Ca2+, Pb2+, Cd2+, Mn2+, Cu2+, Ni2+, and Fe3+ did not interfere	G-quadruplex–hemin (G4–hemin)	[117]

^#For the conversion of limit of detection values into moles per liter (M) the atomic weight of Hg is taken as 200.59 g, MeHg as 215.59 g, EtHg as 229.59 g, and PhHg as 277.59 g.

¹PME: polymeric membrane electrode and CGE: coated graphite electrode.

Analytical instruments: DP-ASV: differential pulse anodic stripping voltammeter; SW-ASV: square wave anodic stripping voltammeter.