Recent Studies on the Speciation and Determination of Mercury in Different Environmental Matrices Using Various Analytical Techniques

Table 1

Analytical parameters of reviewed research papers involving speciation and determination of mercury by spectrometric instruments (AAS, ICP-OES, ICP-MS, AFS, spectrophotometer, and spectrofluorometer).

Analyte	Method	Supporting media	Analytical instrument	LOD	Linearity range	QA/QC studies	Analyzed samples	Interference study	Ref
Hg(II)	Fluorescence	Dithioacetal-substituted triphenylimidazole	Fluorescence spectrometer	4.3 nM	0–10 μM	Sensitivity and selectivity of the method evaluated	—	Cations, such as Ag^+, CO^2+, K^+, Sn^2+, Cu^2+, Ni^2+, Mn^2+, Na^+, Ca^2+, Mg^2+, Pb^2+, Fe^3+, and Cd^2+ did not interfere in determination of Hg^2+	[96]
Hg(II)	Fluorescence	2-Aminoethyl piperazine and 4-chloro-7-nitrobenz-2-oxa-1,3-diazole	Fluorescence spectrometer	0.57 μM	0.00–16.6 μM	The method is selective over 18 metal ions. Recoveries of Hg(II) in water samples in the range of 95–98.2%	Water samples	Either no or a small fluorescence signal was observed for Na^2+, K^2+, Mg^2+, Ca^2+, Al^3+, Ga^3+, In^3+, Cr^3+, Mn^2+, Fe^2+, Fe^3+, Co^2+, Ni^2+, Cu^2+, Zn^2+ Cd^2+, and Pb^2+ ions	[110]
GEM	Acid digestion	Teflon filters	ICP-MS	0.015 M	—	SRM 1633c was analyzed. Recoveries were in the range of 84–112%	Particulate matter	—	[45]
Hg(II)	CVG	LiAlH4, SnCl2/THB	HG-AFS	0.0004 μM		The RSD values were less than 7.0% for 11 measurements. CRMs were analyzed	Soil, water, and human hair samples	10 mg L^−1 for Fe^3+, 20 mg L^−1 for Co^2+, 10 mg L^−1 for Ni^2+, and 20 mg L^−1 for Cu2+. For arsenic and antimony, no interference from 25 mg L^−1 Cu^2+, Co^2+, or Ni^2+ was observed	[89]
Hg(II)	Photochemical vapor generation	—	ICP-OES	0.006 μM	Up to 0.25 μM	Recoveries of Hg(II) in reals samples were in the range of 79–112%	Petroleum production water	K^+, Ba^2+, Sr^2+, Mg^2+, Cu^2+, Pb^2+, and Zn^2+ were over the concentration ranges studied, whereas the presence of Ca^2+, Ni^2+, Sb^3+, As^3+, Se^4+, Fe^3+, and Cr^3+ was significant	[111]
Hg(II)	Acid digestion	—	ICP-MS	—	0.0005–0.5 μM	Precision of the method for Hg2+ is 5.6% with six replicates	Fish samples	Hg(II) was analyzed along with Cd^2+ and Pb^2+	[112]
Total Hg	Wet digestion	—	AAS	—	—	—	Fish samples	Hg(II) was analyzed along with Cd^2+ and Pb^2+	[68]
Hg speciation	Acid digestion	—	ICP-MS	0.00004 μl/L	—	NIST 612 was analyzed	Petroleum hydrocarbons	—	[88]
Total Hg	Chemical vapor generation	Nonionic surfactants	AFS	22.5 μM	—	CRMs (GBW08603, GBW(E) 080401 and GBW(E)080402) were analyzed	Natural water samples	Severe interference of cations was observed at 10 mg L^−1 concentration	[58]
Total Hg	Sequential extraction	—	CV-AAS	—	—	Comparison of the results with other methods was performed	Thar coal	—	[102]
Hg(II)	Aptasensor	Core-shell Ag@SiO2 nanoparticles	AFS	0.33 nM	0–1.2, 1.2–14 nM	Recoveries were over 94% for the determination of Hg(II) in real samples. The RSD values for Hg(II) determinations were lower than 5.1%	Real water samples	Selective in presence of Cd^2+, Pb^2+, Zn^2+, Mn^2+, Co^2+, Fe^2+, Cu^2+, and Ag^+	[113]
Hg(II)	Chemosensor	Porphyrin-thymine conjugates	Luminescence spectrometer	6.7 nM	—	Method reversibility was reported	—	Interference of Zn^2+, Cu^2+, Ni^2+, Mn^2+, Mg^2+, Pb^2+, and Cd^2+ was inhibited	[97]
Hg	PVG and CVG	NaBH4/SnCl2	PVG-AAS, CV-AAS (NaBH4) and CV-AAS (SnCl2)	0.0006, 0.0005, and 0.0002 μM	0.012–0.05 μM	The accuracy was evaluated by assessing recoveries in spiked samples which were in the range of 84–108.3%	Glycerin samples	—	[91]
Total Hg	Solid sampling analysis	—	GF-AAS	0.0014 μl/L	—	SRM (NIST-695) was analyzed. The RSD values were better than 8.2% for five replicates	Phosphate fertilizers	—	[53]
DGM, TGM	—	—	CV-AFS	1.35 × 10^−8 μM (DGM), 1.35 × 10^−8 μM (TGM)	—		Air-sea interface of Minamata	—	[46]
Methyl Hg	Distillation and solvent extraction	KBr/CuSO4	GC-ICP-MS	2.0 × 10^−5μg g^−1	—	CRM of ERM-CC580 was analyzed	Peat soil	—	[59]
Total Hg	Ultrasound extraction	NaBH4/isoamyl alcohol, thiourea	CV-AAS	70 μM	—	The RSD values of Hg determinations in vinegar was less than 8.11%	Vinegar	Vanadium also determined in the same samples	[108]
Total Hg	Slurry sampling		CV-AAS	150 μM	—	The RSD values in the mercury determinations was less than 10.89%. The recoveries were in the range of 85–106%	Iron supplement	—	[103]
Total Hg		NaBH4	AES	0.00004 μg g^−1	—	—	Sea food	—	[69]
Hg(II)	Preconcentration	Metal-organic frame work	CV-AAS	0.05 μM	—	SRMs (DOLT-4 and DORM-2) were analyzed. The RSD values in the determination of Hg(II) was less than 10%	Sea food samples	Majority of cations did not interfere in the determination of Hg(II) at pH 6.25 experimental condition	[54]
Total Hg	Solid sampling	—	HR-AAS	2.0 × 10^−5μg (sediment), 9.6 × 10^−5μg (marine biota)	2.0 × 10^−5–0.004 μg (sediment), 2.0 × 10^−5–0.025 μg (marine biota)	CRMs (PACS-2, IAEA-405, SRM 2703, BCR-464, IAEA-436, DORM-2, MA-ROPME-2/TM) were analyzed	Sediment and marine biota samples	—	[55]
Total Hg	Thermal desorption	—	AAS	0.0006 μg g^−1	—	CRMs (CRM-1515, MESS-3 and TORT-2) were analyzed with recoveries 96.0–104.8%	Fish and sea food samples	—	[60]
Total Hg	ISO guide 34	—	CV-ICP-MS	8.0 × 10^−5μg/g	1.9–50 × 10^−5μg/g	CRM (BCR-579) was analyzed	Sea water	By using cold vapor generation spectral interferences were avoided	[61]
Total Hg	Acid digestion	Nitric and perchloric acid	AAS	0.0004749 μg/g	0.0002–0.01 μM	The mean recovery of Hg was 78.65%. RSD values for interday precision of Hg was 7.17%	Cream cosmetics	Along with Hg, zinc was also determined	[109]
Total Hg	Extraction	NaBH4	CV-AAS	0.003 μM	0.05–0.5 μM	The recoveries of Hg in oil samples were in the range of 80–103%	Oil samples	—	[104]
Total Hg	Thermal desorption	—	TDA-AAS	0.025 μg/g (LOQ)	—	Mean recovery of Hg in real samples was 94.2% and SD was 3.5%	Sea food	—	[105]
Total Hg	Method EPA 7473	Teflon	CV-AFS	0.0006 μg g^−1	0.002–0.08 μg⋅g^−1	CRM (BCR-279) was analyzed and RSD in the determination of Hg in seaweeds is less than 10%	Seaweeds	—	[62]
Hg(II)	Immobilization	Dithizone	FAAS	2.0 × 10^−9 M	1.1 × 10^−8–2.0 × 10^−6M	The coefficients of variation for Hg(II) was found to be 2.7%	Industrial wastewater,; spiked tap water, and natural water	Except Cu^2+, the other ions (Mn^2+, Ni^2+, Pb^2+, Co^2+, Cd^2+, Fe^2+, Fe^3+, and Al^3+) did not interfere up to 50-fold excess	[114]
MeHg	Online preconcentration	—	HPLC-CV-AFS	40000 μM	5–2500 μM	CRMs (NIES CRM no. 13 and IAEA-085) were analyzed. Recoveries of MeHg from real samples were in the range of 91.4–101.8%	Sewage, river, and seawater samples	—	[47]
Hg(II)	Solid phase extraction	Ion imprinted polymeric nanomaterials	CV-AAS	0.18 μM	—	The RSD values for eight replicates was 4.2%	Water and human hair samples	In presence of large amounts of Cu^2+, Ni^2+, Cd^2+, Zn^2+, Mn^2+, Pb^2+, Fe^3+, and Cr^3+ ion Hg(II) was effectively determined	[115]
Hg(II), MeHg	Rapid extraction	—	HPLC-ICPMS	0.0002 (Hg2+), 0.0001 (MeHg) μg g^−1	—	CRMs (TORT-2 and DORM-2) were analyzed	Fish samples	—	[63]
Speciation	Liquid-liquid microextraction	Ionic liquid vortex-assisted	HPLC-CV-AFS	3.4–6.1 × 10^−6 μg/g	0.0001–0.07 μg/g	The RSD values were less than 6.4%	Sediment samples	—	[92]
Total Hg	Solid sampling	—	TDA-AAS	0.001 μg g^−1	0.025–0.2 μg g^−1	Recoveries of Hg from real samples were in the range of 89–99%	Fish and shrimp samples	—	[106]
Hg speciation	Cloud point extraction	Polyethylene glycol	Spectrophotometer	0.045 μM	0.05–0.5 μM	The RSD values of the method were below 2.6%	River water and river sediment	No interference of Cd2+, Bi3+, and Pb2+ was observed in the determination of Hg(II)	[107]
Hg(II)	Colorimetric	1,5-diphenylthiocarbazone	Flow injection spectrophotometer	0.15 μM	0.25–7.5 μM	The results were compared with the data obtained with ICP-MS	Cosmetics and Thai traditional medicines	20-fold Fe^2+, Zn^2+, and Cu^2+, 40-fold Pb^2+, 50-fold Al^3+, Fe^3+, and Mn^2+ did not interfere in the determination of Hg(II)	[94]
Hg(II)	Colorimetric, fluorescence	Calixpyrrole hydrazide	Spectrofluorometer	1 nM	1 nM–1 μM	—	Groundwater and industrial effluent water	No interference of Pb(II), Cd(II), Mn(II), Fe(III), Ni(II), Zn(II), Hg(II), Co(II), and Cu(II) was observed	[70]
Hg(II)	Fluorescence probe	Chitosan hydrogel	Fluorescence spectrophotometer	0.9 nM	5.0–50 nM	—	Water samples	Cations such as Fe^3+, Co^2+, Pb^2+, Cu^2+, Cd^2+, Ni^2+, and Zn^2+ did not interfere in the determination of Hg(II)	[71]
Hg(II)	Fluorescence sensor	CdTe quantum dots	Fluorescence spectrophotometer	4.0 nM	6.0–450 nM	RSD values were less than 4.15%	Lake water samples	Interference of 10-fold Pb^2+, Cu^2+, and Ag^+ was less than 7%	[116]
Hg(II)	Fluorescent chemosensor	DA	Fluorescence spectrophotometer	0.0028 μl/L	—	Theoretical and experimental results were in good agreement with each other	—	Simultaneous determination of Ag+ and Cu2+ was reported	[98]
Hg(II)	Time-gated fluorescent sensing	Thymine	Spectrofluorometer	0.11 nM	0.20–10 nM	Recoveries of Hg(II) in environmental water samples were in the range of 93.75–102.5%	Drinking water samples	No interference of Ag+, Co^2+, Ni^2+, Ca^2+, Cd^2+, Al^3+, Fe^3+, Au^3+, Cr^2+, Mn^2+, Pb^2+, Cu^2+, Mg^2+, Zn^2+, and Ba^2+ was reported	[117]
Hg(II)	Colorimetric	Gold nanoparticles	Spectrophotometer	0.5 nM	0.5–300 nM	CRM (GBW (E) 080392) was analyzed and the recoveries were found in the range of 88.9–106%	Tap water and lake water	Cr^3+, Mn^2+, Co^2+, Ni^2+, Cu^2+, Fe^3+, Zn^2+, Cd^2+, and Pb^2+ ions did not interfere in the determination of Hg^2+	[64]
Hg(II)	Fluorescence	Schiff base	Fluorescence spectrophotometer	2.82 × 10^−6 M	—	Effectiveness of the method was proved by confocal fluorescence microscope	Living cells	—	[95]
Hg(II)	Colorimetric	Silver nanoparticles	Spectrophotometer	1.18 × 10^−9 M	10–50 nM	A good linear correlation ( = 0.9799) was obtained for different concentrations of Hg(II) and absorbance ratio	Lake, seawater, and groundwater	Fe^2+, Fe^3+, Cr^6+, Pb^2+, Mn^2+, Al^3+, Ni^2+, Cr^3+, Cd^2+, Mg^2+, and Zn^2+ did not interfere up to 1000 times of detection limit of Hg(II)	[118]
Hg(II)	Chemosensor	Dimeric binol-based chemosensor	Spectrofluorometer	4.4 × 10^−7M	—	—	Wastewater samples	100 equivalents of Na^+, K^+, Mg^2+, Ce^3+, Ca^2+, Ba^2+, Cd^2+, Mn^2+, Co^2+, Ni^2+, Cu^2+, Cr^3+, Zn^2+, Pb^2+, Fe^2+, Fe^3+, Al^3+, and Ag^+	[72]
Hg(II)	Colorimetric	Bovine serum albumin	Spectrophotometer	7.2 nM	0–120 nM	Results were compared with ICP-MS	Drinking water samples	No interference of Na^+, Mg^2+, Ca^2+, Cd^2+, Mn^2+, Co^2+, Ni^2+, Cu^2+, Zn^2+, Pb^2+, Fe^3+, and Au^3+ was observed	[119]
Hg(II)	Fluorescence	Gold nanocluster	Spectrofluorometer	30 nM	—	Recoveries of Hg(II) in spiked samples were in the range of 97.7–99.3%	Lake water samples	No interference of Na^+, Mg^2+, Ca^2+, Ni^2+, Cu^2+, Zn^2+, Ce^3+, Pt^4+, and Al^3+ was observed	[120]
Hg(II)	Colorimetric	Rhodamine B	Spectrofluorometer	1.71 × 10^−6M	—	—	Spiked tap water samples	Interference of several ions was negligible in the determination of Hg(II)	[73]
Hg(II)	Fluorescence	—	Fluorescence spectrometer	9.56 × 10^−9 M	—	—	—	Hg(II) can be detectable in presence of Fe^3+, Cu^2+, Co^2+, Ni^2+, Cd^2+, Pb^2+, Zn^2+, and Cr^3+	[74]
Hg(II)	Adsorption	Rhodamine	Fluorescence spectrophotometer	3.42 × 10^−6 M	0–6.0 μM	—	Drinking and lake water	No interference of Cd^2+, Co^2+, Cu^2+, Fe^3+, Mn^2+, Ni^2+, Pb^2+, and Zn^2+ at 581 nm	[75]
Hg(II)	Fluorimetric	Coumarinyldithiolane	Fluorescence spectrophotometer	—	0.06–1.5 μM	—	Aqueous solutions	No influence of Al^3+, Zn^2+, Co^2+, Ni^2+, Cu^2+, Cd^2+, Cr^3+, and Pb^2+ on the determination of Hg(II) in presence of probe	[76]
Hg(II)	Fluorescence sensors	Peanut shell	Fluorescence spectrometer	8.5 × 10^−9M	0–19 × 10^−8M	—	Lake water	The method was selective for Hg(II)	[77]
Hg(II)	Colorimetric	L-Arginine	Spectrophotometer	5 nM	1–20 and 20–600 μM	—	Food samples	No interference from Cd^2+, Co^2+, Cu^2+, Ni^2+, and Pb^2+ was observed	[78]

LLME: Liquid-liquid microextraction; CRM: certified reference material; CVG: chemical vapor generation; THB: tetrahydroborate; RSD: relative standard deviation; LOQ: limit of quantification; MIP-OES: microwave-induced plasma optical emission spectrometer; PPT: poly(1,4-bis-(8-(4-phenylthiazole-2-thiol)-octyloxy)-benzene); LSPR: localized surface plasmon resonance; DA: dimethylaminocinnamaldehyde-aminothiourea. Analytical Instruments. CV-AAS: Cloud Vapor Atomic Absorption Spectrometer; GF-AAS: Graphite Furnace AAS; ICP-OES: Inductively Coupled Plasma Optical Emission Spectrometer; ICP-MS: ICP-Mass Spectrometer; ICP-AES: ICP-Atomic Emission Spectrometer; HPLC: High Performance Liquid Chromatography; AFS: Atomic Fluorescence Spectrometer.