Table 1.
Analytical parameters of reviewed research papers about the speciation and determination of mercury by spectrometric instruments (AAS, ICP-OES, AES, MS, and AFS).
| S. number | Analyte | Analytical instrument used for the detection | Method | Limit of detection (LOD)# | Linearity range | Analyzed samples | Interference study | Supporting media | Reference |
|---|---|---|---|---|---|---|---|---|---|
| 1 | Total Hg | CV-AAS and ICP-AES | Microwave acid digestion | 4.83 × 10−10 M | — | Fish samples | Cadmium and lead also analyzed along with mercury | — | [7] |
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| 2 | Hg(II) | CV-AAS | Preconcentration | 1.79 × 10−10 M | — | Water and human hair | Recovery of Hg2+ is in the range of 95.6–104.9% in presence of Cu2+, Co2+, Zn2+, Ni2+, Cd2+, Mn2+, Ba2+, Pb2+, Fe3+, Cr3+, Al3+, Ag+, K+, Na+, NH4 +, Mg2+, and Ca2+ ions, from 750 to 2500-fold | Dithizone | [8] |
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| 3 | Total Hg | CV-AAS | Ultrasound extraction | 6.98 × 10−11 M | — | Alcohol vinegar | — | — | [9] |
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| 4 | Total Hg | CV-AAS | SPE1 | 4.98 × 10−11 M | Rice, canned fish, and tea leaves | The tolerance limit for Na+, K+, Mg2+, and Ca2+ is 4000-fold, for Ba2+ and Zn2+ is 40-fold, for Fe3+, Cr3+, Co2+, and Ni2+ is 10-fold, and for Al3+ is 200-fold compared to Hg2+ | Fe3O4 nanoparticles | [10] | |
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| 5 | Hg(II) | CV-AAS | SPE | 9.97 × 10−12 M | Up to 500 μg L−1 | Water samples | As, Al, Fe, Mo, and Sb are depressed the Hg signal | Carbon nanotubes | [11] |
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| 6 | Total Hg | CV-AAS | Acid digestion | 3.6 × 10−9 M | — | Marine fish | — | — | [12] |
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| 7 | Total Hg | CV-AAS | Wet digestion | 3.0 × 10−9 M | — | Green tiger shrimp | Arsenic also determined along with mercury | — | [13] |
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| 8 | Total Hg | CV-AAS | Alkaline fusion digestion | 0.06 ng g−1 | 0.006–4000 ng g−1 | Phosphate rock | — | — | [14] |
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| 9 | THg | AAS | Acid digestion | 4.98 × 10−12 M | — | Fish muscle tissues | Cadmium and lead also detected along with mercury | — | [15] |
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| 10 | Hg(II) | CV-AAS | SPE | 1.19 × 10−11 M | 0.01–2.30 μg L−1 | Water samples | Fe3+, Cu2+, Zn2+, Cd2+, Co2+, and Mn2+ are not interfered up to 5 mg L−1 and NH4 + and Tl3+ are not interfered up to 1 mg L−1 | Polymer supported ionic liquid | [16] |
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| 11 | Hg(II) | CV-AAS | SPE | 9.97 × 10−11 M | 0.07–2.00 μg L−1 | Water samples | Tolerable amount of major metals is limited up to 50 μg L−1 | Polytetrafluoroethylene | [17] |
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| 12 | Total Hg | CV-AAS | Digestion | 3.98 × 10−10 M | 2.5–10.0 μg L−1 | Biological samples | — | Cold finger | [18] |
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| 13 | Total Hg | CV-AAS | Combustion | 2.99 × 10−13 M | — | Water and fish | Arsenic and selenium also determined along with mercury | — | [19] |
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| 14 | Total Hg | AAS | Amalgamation | 0.2 ng/g for hair and 0.02 ng/g for blood | — | Hair and blood samples | Arsenic and selenium also determined along with mercury | — | [20] |
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| 15 | Total Hg | CV-AAS (total Hg) and GC-ICPMS (MeHg) | Cold-vapor reduction with NaBH4 | 5.98 × 10−11 M (total Hg) and 2.3 × 10−9 M (MeHg) | — | Blood of birds | Selenium also determined along with mercury and methylmercury | — | [21] |
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| 16 | Total Hg and MeHg | CV-AAS (total Hg) and CV-AFS (MeHg) | Digestion | 0.03–0.1 ng/g | — | Fish, vegetables, and mushrooms | Selenium and cadmium also determined with mercury species | — | [22] |
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| 17 | Hg speciation | CV-AAS (total Hg) and CV-AFS (MeHg) | Acid digestion | — | Water samples | — | — | [23] | |
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| 18 | Hg speciation | CV-AAS | LLME2 | 1.49 × 10−10 M (Hg2+) and 1.8 × 10−9 M (MeHg) |
0.5–100 ng mL−1 | Water samples and CRMs | The recovery of Hg2+ in presence of foreign ions is 95–105 and for MeHg is 96–106% | — | [24] |
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| 19 | Total Hg | GF-AAS | Acid mineralization | 6.97 × 10−11 M | — | Fish muscle samples | — | Copper nitrate | [25] |
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| 20 | GEM | AAS | Ambient air | — | — | [26] | |||
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| 21 | Total Hg | CV-AAS | Acid digestion | 0.0006 μg g−1 | — | Freshwater fish samples | — | Stannous chloride | [27] |
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| 22 | Total Hg | AAS | Combustion | 0.01 ng | — | Soil samples | Interference of various heavy metals was overcome by using sample pretreatment | — | [28] |
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| 23 | Hg speciation | AAS (THg) and ICP-MS-HPLC (MeHg) | Hydride generation | 5.33 × 10−14 M | 20 μg L−1 | Fish samples | Cd, Pb, As, and Sn also measured along with Hg | — | [29] |
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| 24 | THg | HG-AAS | Hydride generation | 98.4% (accuracy) | — | Irrigation water wells | Along with mercury Pb, Cd, and Al Cr also measured | — | [30] |
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| 25 | THg | CV-AAS and AAS | Thermal decomposition and amalgamation | 1.34 × 10−9 M (TD-amalgamation AAS) and 3.14 × 10−9 M (CV-AAS), | — | Soil samples | — | — | [31] |
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| 26 | Total Hg speciation | HV-AAS and HPLC-CV-AFS |
Extraction | — | — | Aqueous solutions and fish tissue | — | Multiwalled carbon nanotubes | [32] |
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| 27 | Total Hg | CV-AAS (DMA) | Microwave oven digestion | — | — | Canned fish | Selenium and tin also measured along with mercury | — | [33] |
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| 28 | THg | AMA (AAS) | AAS principles and without digestion process | — | — | Fish red muscle and white muscle |
— | — | [34] |
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| 29 | THg | AES | LIBS and SIBS | 2 × 10−3 M (LIBS) and 9.97 × 10−5 M (SIBS) | Soil samples | At 534.074 nm has less spectral interference | — | [35] | |
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| 30 | Hg speciation | CV-AFS | Extraction | 1.0 (total Hg) and 0.01 MeHg ng g−1 | — | Sea water and sediments | — | — | [36] |
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| 31 | Hg speciation | CV-AFS | Extraction | 0.01 × 10−12 M (Hg0) and 0.002 × 10−12 M (DM Hg) | — | Sea waters | — | — | [37] |
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| 32 | Total Hg | CV-AFS | Microwave assisted digestion | 3.98 × 10−13 M | — | Nuts | Interference of fat in nuts is removed by treatment with chloroform and methanol | — | [38] |
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| 33 | Hg(II) | AFS | Fluorescence optical sensor | 9.57 × 10−12 M | 2.27 × 10−11–1.13 × 10−3 M | Human hair, urine, and well water samples |
Most of the alkali, alkaline, and transition metal ions did not interfere in the determination of Hg2+ | N-(2-Hydroxy phenyl)-N-(2-mercapto phenyl)-o-phthalylidene | [39] |
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| 34 | GEM | CV-AFS | Gold amalgamation | 0.0002 ng | — | Total suspended particulates | — | QFF (quartz fiber filters) | [40] |
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| 35 | MeHg | AAS and CV-AFS | Acid digestion | 0.005 μg/g | — | Water, soil, sediments, and foodstuffs | — | — | [41] |
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| 36 | Total Hg | CV-AFS | Microwave assisted digestion | 0.5 ng g−1 | — | Sediments | — | Sequential injection system | [42] |
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| 37 | Total Hg | CV-AFS | Acid digestion | 0.48 ng g−1 | — | Rice | Interference of other metal ions is eliminated by acid wash and kept storage of samples for 24 h | Multisyringe flow injection analysis | [43] |
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| 38 | Hg speciation | HPLC-AFS | UV-induced atomization | 1.9 × 10−9 (Hg2+), 1.9 × 10−9 (MeHg), and 2.0 × 10−9 (EtHg) M | CRMs | — | — | [44] | |
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| 39 | Hg(II) | UV-AFS | SPE | 1.49 × 10−13–3.98 × 10−13 M | 1–5000 ng L−1 | Natural waters | 10 mg L−1 of Fe2+, Fe3+, Cu2+, Pb2+, and As3+ and 10 g L−1 of Na+, K+, and Ca2+ did not interfere in the determination of 100 ng L−1 of Hg2+ | Sodium diethyldithiocarbamate | [45] |
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| 40 | Hg(II) | AFS | Micro-SPE | 5.98 × 10−11 M | Up to 5 μg L−1 | Water samples | — | Mesofluidic platform | [46] |
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| 41 | Hg speciation | EX-AFS | 0.5 ng g−1 (total Hg) | — | Waste calcines | — | — | [47] | |
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| 42 | Hg speciation | CV-AFS | Extraction | ~0.5 pg | — | Atmospheric air | — | PTFE filter papers | [48] |
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| 43 | MeHg | GC-AFS | SPE | 12 ng g−1 | Up to 1.5 ng mL−1 | Biological samples | — | — | [49] |
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| 44 | Hg speciation | HPLC-AFS | Liquid-liquid microextraction | 1.54 × 10−10 (Hg2+), 7.42 × 10−11 (MeHg), 1.045 × 10−10 (EtHg), and 3.31 × 10−10 M (PhHg) | 0.0–20 μg L−1 | Environmental waters | No interference from other metal ions | 1-Octyl-3-meth-l imidazolium hexafluorophosphate | [50] |
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| 45 | MeHg | CV-AFS | Extraction | 0.515 ng g−1 | — | Petroleum | — | TMAH3, KOH/CH3OH, HCl, and acidic CuSO4/KBr | [51] |
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| 46 | GEM | CV-AFS | — | — | — | Ambient air | — | — | [52] |
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| 47 | Hg(II) | AFS | Fluorescence | 0.07 × 10−6 M | 0.1–4.5 μM | Aqueous solutions | Longer excitation and emission wavelength could shield the interference | Fe3O4 magnetic nanoparticles | [53] |
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| 48 | Hg speciation | CV-AFS | Thermal decomposition | — | — | Fish liver | Method validity is tested with CRM | — | [54] |
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| 49 | THg | AFS | — | <4.98 × 10−12 M | — | Snow | — | K2Cr2O7/SnCl2 | [55] |
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| 50 | Atmospheric Hg | CV-AFS | Extraction | — | — | Particulate matter | — | — | [56] |
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| 51 | THg | CV-AFS | Flow injection mercury system | — | — | Herbal products | — | Protease papain | [57] |
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| 52 | Hg speciation | LC-UV-CV-AFS | Microwave digestion | 4.98 × 10−12 (total Hg), 1.39 × 10−12 (MeHg), and 1.99 × 10−12 (Hg2+) M | — | Sea food | Simultaneously determined both Hg(II) and MeHg | — | [58] |
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| 53 | MeHg and total Hg | CV-AAS | Digestion | 0.088 (MeHg) and 0.005 (total Hg) μg g−1 | — | Hair and milk of mothers | — | — | [59] |
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| 54 | Hg(II) | ICP-MS | Microfluidic | 3.49 × 10−10 M | 0.2–4.0 μg L−1 | Aqueous samples | The recovery of Hg2+ in the presence of 100 μg L−1 of Ca2+, Cd2+, Co2+, Cr3+, Cu2+, K+, Mg2+, Na+, Ni2+, Pb2+, and Zn2+ is in the range of 97.5–101.7% | Gold nanoparticles | [60] |
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| 55 | Total Hg | ICP-MS | Acid digestion | 0.053–0.01 μg g−1 | — | Pharmaceutical ingredients | Low residual carbon content in digests is desirable to minimize some interference | — | [61] |
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| 56 | Hg(II) | ICP-MS | Adsorption | — | — | Wastewaters | — | Multiwalled carbon nanotubes | [62] |
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| 57 | Hg(II) | ICP-OES | Extraction | 1.49 × 10−11 M | — | Fish samples | Selective in presence of Na+, K+, Cs+, Ca2+, Mg2+, Zn2+, Fe2+, Cu2+, Co2+, Ni2+, Mn2+, Cd2+, and Pb2+ into 1 mg L−1 solutions of Hg(II) in pH 8 | Ion imprinted polymer | [63] |
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| 58 | Total Hg | CV-ICP-MS | Microwave digestion | 3 ng g−1 | — | Plants and soil | — | — | [64] |
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| 59 | Total Hg | ICP-MS | Microwave assisted digestion | — | — | Rice | — | — | [65] |
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| 60 | GEM | CV-ICP-MS | Thermal analysis | 20 × 10−15 g | — | Atmospheric particulates | — | — | [66] |
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| 61 | Hg(II) and MeHg | HPLC-ICPMS | HF-LPME4 | 5.48 × 10−10 (Hg2+) and 1 × 10−9 (MeHg) M | Up to 50 μg L−1 | Tap, river, and estuarine waters | Simultaneously selenium also determined along with mercury | — | [67] |
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| 62 | Hg speciation | ICP-MS | Ion exchange chromatography | 9.47 × 10−11 (Hg2+), 1.25 × 10−10 (MeHg), 1.35 × 10−10 (EtHg), and 7.92 × 10−10 (PhHg) M | 0.1–100 μg L−1 (all Hg species) | Sea water and marine fish | — | L-Cysteine or thiourea | [68] |
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| 63 | Hg speciation | GC-ICP-MS | Preconcentration | 27 (Hg2+) and 12 ng g−1 (MeHg) | — | Human hair | — | — | [69] |
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| 64 | Total Hg | MC-ICPMS | Isotope ratio analysis | 0.1–0.2 disintegrations per minute | — | Sediment core | Mercury and mercury isotope compositions are determined | — | [70] |
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| 65 | Hg(II) and MeHg | CVG-ICP-MS | Extraction | 1.7 (Hg(II)) and 2.3 ng g−1 (MeHg) | — | Fish samples | — | — | [71] |
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| 66 | MeHg, Hg(II), and EtHg |
HPLC-CV-ICPMS | Extraction and separation | 5.98 × 10−11 (Hg(II)), 2.17 × 10−11 (EtHg), and 1.8 × 10−8 (MeHg) M | — | Plasma/serum samples | — | — | [72] |
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| 67 | Total Hg | ICP-MS | Microwave assisted digestion | — | — | Freshwater fish samples | — | — | [73] |
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| 68 | Total Hg | ICP-MS | Isotope dilution and UV-photochemical vapor generation | 0.5 pg g−1 | — | Biological tissues | Polyatomic interference is not detectable | Formic acid | [74] |
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| 69 | Total Hg | ICP-MS | Calcination-isotope dilution | 2 × 10−15 M | — | Diploria specimens | No isobaric interference was found | — | [75] |
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| 70 | Hg speciation | ICP-MS | Anion exchange chromatographic separation | 3.98 × 10−11 (Hg2+), 1.11 × 10−10 (MeHg), 1.26 × 10−10 (EtHg), and 1.22 × 10−10 (PhHg) M | — | Fish samples | — | 3-Mercapto-1-propanesulfonate | [76] |
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| 71 | Total Hg | ICP-MS | Ultrasonic slurry sampling electrothermal vaporization | 0.2 ng g−1 | — | Herbal samples | As, Cd, and Pb also determined along with Hg | 8-Hydroxyquinoline | [77] |
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| 72 | Total Hg | ICP-MS | Electrothermal vaporization | 5.98 × 10−11 M | — | Water associated with crude oil production | By preconcentration of analyte interference is avoided | — | [78] |
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| 73 | THg | ICP-MS | Isotope dilution equation | 4.98 × 10−11 M for THg | 0.0005–1.321 mg/kg for MeHg | Arctic cod | — | — | [79] |
#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.
1Solid-phase extraction; 2LLME: liquid-liquid microextraction; 3TMAH: tetramethylammonium hydroxide; 4HF-LPME: hallow fiber liquid phase microextraction.
Analytical instruments: CV-AAS: cloud vapor atomic absorption spectrometer; HG-AAS: hydride generation AAS; 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; AMA: automatic mercury analyzer; DMA: direct mercury analyzer.