Comparison of Simultaneous Quantitative Analysis of Methylmercury and Inorganic Mercury in Cord Blood Using LC-ICP-MS and LC-CVAFS: The Pilot Study of the Japan Environment and Children’s Study
Abstract
:1. Introduction
2. Materials and Methods
2.1. Study Participants and Blood Collection
2.2. Mercury Speciation Analysis
2.2.1. LC-ICP-MS Analysis
2.2.2. LC-CVAFS Analysis
2.3. Other Mercury Analysis
2.4. Quality Control
2.5. Data Analysis
3. Results
4. Discussions
5. Conclusions
Supplementary Materials
Author Contributions
Funding
Institutional Review Board Statement
Informed Consent Statement
Data Availability Statement
Acknowledgments
Conflicts of Interest
References
- Satoh, H. Mercury. In Aging and Vulnerability to Environmental Chemicals; Bernard, W., Ed.; The Royal Society of Chemistry: Shanghai, China, 2012; Volume 16, pp. 125–150. [Google Scholar]
- NRC National Research Council. Toxicological Effects of Methylmercury; National Academy Press: Washington, DC, USA, 2000. [Google Scholar]
- Karita, K.; Sakamoto, M.; Yoshida, M.; Tatsuta, N.; Nakai, K.; Iwai-Shimada, M.; Iwata, T.; Maeda, E.; Yaginuma-Sakurai, K.; Satoh, H.; et al. Recent Epidemiological Studies on Methylmercury, Mercury and Selenium. Jpn. J. Hyg. 2016, 71, 236–251. [Google Scholar] [CrossRef] [PubMed] [Green Version]
- WHO. Methylmercury; World Health Organization: Geneva, Switzerland, 1990. [Google Scholar]
- Tatsuta, N.; Murata, K.; Iwai-Shimada, M.; Yaginuma-Sakurai, K.; Satoh, H.; Nakai, K. Psychomotor Ability in Children Prenatally Exposed to Methylmercury: The 18-Month Follow-Up of Tohoku Study of Child Development. Tohoku J. Exp. Med. 2017, 242, 1–8. [Google Scholar] [CrossRef] [PubMed] [Green Version]
- Tatsuta, N.; Nakai, K.; Murata, K.; Suzuki, K.; Iwai-Shimada, M.; Kurokawa, N.; Hosokawa, T.; Satoh, H. Impacts of prenatal exposures to polychlorinated biphenyls, methylmercury, and lead on intellectual ability of 42-month-old children in Japan. Environ. Res. 2014, 133, 321–326. [Google Scholar] [CrossRef] [PubMed]
- Akagi, H.; Castillo, E.S.; Cortes-Maramba, N.; Francisco-Rivera, A.T.; Timbang, T.D. Health assessment for mercury exposure among schoolchildren residing near a gold processing and refining plant in Apokon, Tagum, Davao del Norte, Philippines. Sci. Total. Environ. 2000, 259, 31–43. [Google Scholar] [CrossRef]
- Ministry of the Environment Japan. Mercury Analysis Manual; Ministry of the Environment: Tokyo, Japan, 2004.
- Baxter, D.C.; Faarinen, M.; Österlund, H.; Rodushkin, I.; Christensen, M. Serum/plasma methylmercury determination by isotope dilution gas chromatography-inductively coupled plasma mass spectrometry. Anal. Chim. Acta 2011, 701, 134–138. [Google Scholar] [CrossRef]
- Brombach, C.-C.; Gajdosechova, Z.; Chen, B.; Brownlow, A.; Corns, W.T.; Feldmann, J.; Krupp, E.M. Direct online HPLC-CV-AFS method for traces of methylmercury without derivatisation: A matrix-independent method for urine, sediment and biological tissue samples. Anal. Bioanal. Chem. 2015, 407, 973–981. [Google Scholar] [CrossRef]
- De Souza, S.S.; Campiglia, A.D.; Barbosa, F. A simple method for methylmercury, inorganic mercury and ethylmercury determination in plasma samples by high performance liquid chromatography–cold-vapor-inductively coupled plasma mass spectrometry. Anal. Chim. Acta 2013, 761, 11–17. [Google Scholar] [CrossRef]
- Dórea, J.G.; Wimer, W.; Marques, R.C.; Shade, C. Automated Speciation of Mercury in the Hair of Breastfed Infants Exposed to Ethylmercury from Thimerosal-Containing Vaccines. Biol. Trace Element Res. 2010, 140, 262–271. [Google Scholar] [CrossRef]
- Rodrigues, J.L.; De Souza, S.S.; Souza, V.C.d.O.; Barbosa, F., Jr. Methylmercury and inorganic mercury determination in blood by using liquid chromatography with inductively coupled plasma mass spectrometry and a fast sample preparation procedure. Talanta 2010, 80, 1158–1163. [Google Scholar] [CrossRef]
- Michikawa, T.; Nitta, H.; Nakayama, S.F.; Yamazaki, S.; Isobe, T.; Tamura, K.; Suda, E.; Ono, M.; Yonemoto, J.; Iwai-Shimada, M.; et al. Baseline Profile of Participants in the Japan Environment and Children’s Study (JECS). J. Epidemiol. 2018, 28, 99–104. [Google Scholar] [CrossRef] [Green Version]
- Nakayama, S.F.; Isobe, T.; Iwai-Shimada, M.; Kobayashi, Y.; Nishihama, Y.; Taniguchi, Y.; Sekiyama, M.; Michikawa, T.; Yamazaki, S.; Nitta, H.; et al. Poly- and perfluoroalkyl substances in maternal serum: Method development and application in Pilot Study of the Japan Environment and Children’s Study. J. Chromatogr. A 2020, 1618, 460933. [Google Scholar] [CrossRef]
- Sogame, Y.; Tsukagoshi, A. Development of a liquid chromatography-inductively coupled plasma mass spectrometry method for the simultaneous determination of methylmercury and inorganic mercury in human blood. J. Chromatogr. B 2020, 1136, 121855. [Google Scholar] [CrossRef]
- Nakayama, S.F.; Iwai-Shimada, M.; Oguri, T.; Isobe, T.; Takeuchi, A.; Kobayashi, Y.; Michikawa, T.; Yamazaki, S.; Nitta, H.; The Japan Environment and Children’s Study Group; et al. Blood mercury, lead, cadmium, manganese and selenium levels in pregnant women and their determinants: The Japan Environment and Children’s Study (JECS). J. Expo. Sci. Environ. Epidemiol. 2019, 29, 633–647. [Google Scholar] [CrossRef] [Green Version]
- Currie, L.A. Detection and quantification limits: Origins and historical overview. Anal. Chim. Acta 1999, 391, 127–134. [Google Scholar] [CrossRef]
- Abad, S.Q.; Rodríguez-González, P.; Davis, W.C.; Alonso, J.I.G. Development of a Common Procedure for the Determination of Methylmercury, Ethylmercury, and Inorganic Mercury in Human Whole Blood, Hair, and Urine by Triple Spike Species-Specific Isotope Dilution Mass Spectrometry. Anal. Chem. 2017, 89, 6731–6739. [Google Scholar] [CrossRef]
- Wiseman, C.; Parnia, A.; Chakravartty, D.; Archbold, J.; Copes, R.; Cole, D. Total, methyl and inorganic mercury concentrations in blood and environmental exposure sources in newcomer women in Toronto, Canada. Environ. Res. 2019, 169, 261–271. [Google Scholar] [CrossRef]
- CDC. Fourth National Report on Human Exposure to Environmental Chemicals. Available online: https://www.cdc.gov/exposurereport/pdf/FourthReport_UpdatedTables_Volume1_Jan2017.pdf (accessed on 7 April 2021).
- Choi, W.; Kim, S.; Baek, Y.-W.; Choi, K.; Lee, K.; Kim, S.; Yu, S.D.; Choi, K. Exposure to environmental chemicals among Korean adults-updates from the second Korean National Environmental Health Survey (2012–2014). Int. J. Hyg. Environ. Health 2017, 220, 29–35. [Google Scholar] [CrossRef] [Green Version]
- Thomas, S.; Arbuckle, T.E.; Fisher, M.; Fraser, W.D.; Ettinger, A.; King, W. Metals exposure and risk of small-for-gestational age birth in a Canadian birth cohort: The MIREC study. Environ. Res. 2015, 140, 430–439. [Google Scholar] [CrossRef] [Green Version]
- Iwai-Shimada, M.; Kameo, S.; Nakai, K.; Yaginuma-Sakurai, K.; Tatsuta, N.; Kurokawa, N.; Nakayama, S.F.; Satoh, H. Exposure profile of mercury, lead, cadmium, arsenic, antimony, copper, selenium and zinc in maternal blood, cord blood and placenta: The Tohoku Study of Child Development in Japan. Environ. Health Prev. Med. 2019, 24, 1–11. [Google Scholar] [CrossRef] [Green Version]
- Ask, K.; Akesson, A.; Berglund, M.; Vahter, M. Inorganic mercury and methylmercury in placentas of Swedish women. Environ. Health Perspect. 2002, 110, 523–526. [Google Scholar] [CrossRef] [Green Version]
- Grandjean, P.; Weihe, P.; White, R.F.; Debes, F.; Araki, S.; Yokoyama, K.; Murata, K.; Sørensen, N.; Dahl, R.; Jørgensen, P.J. Cognitive Deficit in 7-Year-Old Children with Prenatal Exposure to Methylmercury. Neurotoxicol. Teratol. 1997, 19, 417–428. [Google Scholar] [CrossRef]
- Myers, G.J.; Davidson, P.W.; Cox, C.; Shamlaye, C.F.; Palumbo, D.; Cernichiari, E.; Sloane-Reeves, J.; Wilding, G.E.; Kost, J.; Huang, L.-S.; et al. Prenatal methylmercury exposure from ocean fish consumption in the Seychelles child development study. Lancet 2003, 361, 1686–1692. [Google Scholar] [CrossRef]
- Apel, P.; Angerer, J.; Wilhelm, M.; Kolossa-Gehring, M. New HBM values for emerging substances, inventory of reference and HBM values in force, and working principles of the German Human Biomonitoring Commission. Int. J. Hyg. Environ. Health 2017, 220, 152–166. [Google Scholar] [CrossRef] [Green Version]
- Ou, L.; Chen, L.; Chen, C.; Yang, T.; Wang, H.; Tong, Y.; Hu, D.; Zhang, W.; Long, W.; Wang, X. Associations of methylmercury and inorganic mercury between human cord blood and maternal blood: A meta-analysis and its application. Environ. Pollut. 2014, 191, 25–30. [Google Scholar] [CrossRef]
- Sakamoto, M.; Murata, K.; Kubota, M.; Nakai, K.; Satoh, H. Mercury and heavy metal profiles of maternal and umbilical cord RBCs in Japanese population. Ecotoxicol. Environ. Saf. 2010, 73, 1–6. [Google Scholar] [CrossRef]
- Stern, A.H.; Smith, A.E. An assessment of the cord blood:maternal blood methylmercury ratio: Implications for risk assessment. Environ. Health Perspect. 2003, 111, 1465–1470. [Google Scholar] [CrossRef] [Green Version]
- Aschner, M.; Aschner, J.L. Mercury neurotoxicity: Mechanisms of blood-brain barrier transport. Neurosci. Biobehav. Rev. 1990, 14, 169–176. [Google Scholar] [CrossRef]
- Sakamoto, M.; Chan, H.M.; Domingo, J.L.; Kubota, M.; Murata, K. Changes in body burden of mercury, lead, arsenic, cadmium and selenium in infants during early lactation in comparison with placental transfer. Ecotoxicol. Environ. Saf. 2012, 84, 179–184. [Google Scholar] [CrossRef]
- Oskarsson, A.; Schütz, A.; Skerfving, S.; Hallén, I.P.; Ohlin, B.; Lagerkvist, B.J. Total and Inorganic Mercury in Breast Milk and Blood in Relation to Fish Consumption and Amalgam Fillings in Lactating Women. Arch. Environ. Health Int. J. 1996, 51, 234–241. [Google Scholar] [CrossRef]
- Nordberg, M.; Nordberg, G.F. Toxicological aspects of metallothionein. Cell. Mol. Boil. 2000, 46, 451–463. [Google Scholar]
- Lee, S.; Shin, M.; Hong, Y.-C.; Kim, J.H. Temporal variability of blood lead, mercury, and cadmium levels in elderly panel study (2008–2014). Int. J. Hyg. Environ. Health 2017, 220, 407–414. [Google Scholar] [CrossRef] [PubMed]
- Yaginuma-Sakurai, K.; Murata, K.; Iwai-Shimada, M.; Nakai, K.; Kurokawa, N.; Tatsuta, N.; Satoh, H. Hair-to-blood ratio and biological half-life of mercury: Experimental study of methylmercury exposure through fish consumption in humans. J. Toxicol. Sci. 2012, 37, 123–130. [Google Scholar] [CrossRef] [PubMed] [Green Version]
LC-CVAFS | LC | Shimadzu, Prominence LC-20A |
Colum | Luna 5U C18(2) 100A 50 × 30 mm (Phenomenex) | |
Mobile phase | Methanol: acetonitrile: ultrapure water (38:30:32, v/v) + 1.5 mM ammonium pyrrolidinedithiocarbamate | |
Flow rate | 0.5 mL/min | |
Injection volume | 100 μL | |
Analytical time | 10 min | |
CVAFS | PSA 10.025 MILLENNIUM MERLIN | |
Acid carrier | 10% hydrochloric acid + 10% bromine, 2.5 mL/min | |
Reductant | 2% tin (II) chloride in 10% hydrochloric acid, 4.5 mL/min | |
Post collum | UV digestion, 75 °C | |
LC-ICP-MS | LC | Agilent 1260 Infinity II Bio-inert LC system |
Column | ZORBAX SB-C18, 50 mm × 4.6 mm i.d., 1.8 μm | |
Column temperature | 15 °C | |
Mobile phase | 5% (v/v) methanol, 0.1% (v/v) 2-mercaptoethanol, and 0.018% (v/v) hydrochloric acid | |
Flow rate | 1.0 mL/min | |
Injection volume | 10 μL | |
Cold vapor | 0.08% (w/v) sodium tetrahydroborate in 0.06% (w/v) sodium hydroxide | |
Flow rate | 0.2 mL/min | |
Valve switching mode | 0–3 min: ultrapure water (100%) 3–8.7 min: 0.08% (w/v) sodium tetrahydroborate (100%) 8.7–10 min: ultrapure water (100%) | |
ICP-MS | Agilent 7900 | |
Spray chamber temperature | 2 °C | |
Nebulizer gas flow rate | 0.66 L/min | |
RF power | 1600 W | |
Plasma gas (Ar) flow rate | 15 L/min | |
Auxiliary plasma gas (Ar) flow rate | 0.90 L/min | |
Option gas (20% O2 in Ar) | 5% | |
Isotopes monitored | 202Hg, 196Hg, and 205Tl |
Low Level Sample | LC-ICP-MS, ng/mL | LC-CVAFS, ng/mL | ||
---|---|---|---|---|
MeHg | IHg | MeHg | IHg | |
1 | 0.16 | 0.12 | 0.34 | 0.46 |
2 | 0.16 | 0.11 | 0.32 | 0.46 |
3 | 0.14 | 0.10 | 0.32 | 0.51 |
4 | 0.14 | 0.10 | 0.35 | 0.46 |
5 | 0.15 | 0.11 | 0.40 | 0.40 |
6 | 0.16 | 0.11 | 0.31 | 0.43 |
7 | 0.14 | 0.11 | 0.30 | 0.40 |
Mean | 0.15 | 0.11 | 0.33 | 0.45 |
SD | 0.009 | 0.006 | 0.031 | 0.036 |
MDL | 0.04 | 0.02 | 0.12 | 0.14 |
LC-ICP-MS | Sample | Run 1 | Run 2 | Run 3 | Run 4 | Run 5 | Run 6 | Run 7 |
MeHg | QC-1 | 3.99 | 3.93 | 4.21 | 4.03 | 3.58 | 4.23 | 3.79 |
QC-2 | 3.79 | 3.54 | 3.95 | 4.19 | 4.01 | 4.20 | 3.93 | |
QC-3 | 3.61 | 3.98 | 3.92 | 4.26 | 4.12 | 4.23 | 4.06 | |
QC-4 | 3.77 | 3.85 | 4.08 | 3.97 | 3.95 | 4.07 | 4.03 | |
QC-5 | 3.92 | 3.98 | 4.22 | 4.28 | 3.39 | 3.92 | 3.91 | |
RSD (%) | 3.8 | 4.8 | 3.4 | 3.4 | 8.1 | 3.3 | 2.7 | |
RSD Total (%) | 5.2 | |||||||
IHg | QC-1 | 0.51 | 0.51 | 0.48 | 0.50 | 0.45 | 0.54 | 0.51 |
QC-2 | 0.50 | 0.48 | 0.49 | 0.48 | 0.43 | 0.53 | 0.50 | |
QC-3 | 0.50 | 0.50 | 0.49 | 0.52 | 0.44 | 0.51 | 0.50 | |
QC-4 | 0.52 | 0.49 | 0.50 | 0.49 | 0.43 | 0.51 | 0.51 | |
QC-5 | 0.53 | 0.49 | 0.51 | 0.50 | 0.45 | 0.52 | 0.50 | |
RSD (%) | 2.5 | 2.3 | 2.3 | 3.0 | 2.3 | 2.5 | 1.1 | |
RSD Total (%) | 5.4 | |||||||
LC-CVAFS | Sample | Run 1 | Run 2 | Run 3 | ||||
MeHg | QC-1 | 3.82 | 3.69 | 3.84 | ||||
QC-2 | 3.99 | 3.71 | 3.76 | |||||
QC-3 | 3.87 | 3.69 | 3.87 | |||||
QC-4 | 3.81 | 3.57 | 3.89 | |||||
QC-5 | 3.74 | 3.74 | 3.87 | |||||
RSD (%) | 2.4 | 1.8 | 1.3 | |||||
RSD Total (%) | 2.8 | |||||||
IHg | QC-1 | 4.90 | 4.58 | 5.04 | ||||
QC-2 | 4.78 | 4.53 | 5.06 | |||||
QC-3 | 4.60 | 4.63 | 4.97 | |||||
QC-4 | 4.79 | 4.56 | 4.91 | |||||
QC-5 | 4.86 | 5.00 | 5.03 | |||||
RSD (%) | 2.4 | 4.2 | 1.2 | |||||
RSD Total (%) | 4.0 |
N | ≥MDL (n) | P5 | P25 | Median | P75 | P95 | |||
---|---|---|---|---|---|---|---|---|---|
Cord blood | LC-ICPMS | MeHg (ng/mL) | 366 | 366 | 2.49 | 4.40 | 6.27 | 9.26 | 15.1 |
(ng/g) | 366 | 366 | 2.40 | 4.20 | 6.04 | 8.79 | 14.5 | ||
IHg (ng/mL) | 366 | 355 | 0.08 | 0.14 | 0.21 | 0.30 | 0.50 | ||
(ng/g) | 366 | 355 | 0.08 | 0.14 | 0.20 | 0.28 | 0.49 | ||
LC-CVAFS | MeHg (ng/mL) | 50 | 50 | 1.57 | 4.52 | 6.26 | 8.12 | 14.7 | |
(ng/g) | 50 | 50 | 1.56 | 4.47 | 6.21 | 8.15 | 14.7 | ||
IHg (ng/mL) | 50 | 39 | <MDL | 0.16 | 0.29 | 0.40 | 0.74 | ||
(ng/g) | 50 | 39 | <MDL | 0.16 | 0.29 | 0.40 | 0.74 | ||
Maternal blood | LC-ICPMS | MeHg (ng/mL) | 101 | 101 | 1.87 | 3.25 | 5.39 | 8.25 | 14.7 |
(ng/g) | 101 | 101 | 1.79 | 3.12 | 5.18 | 7.95 | 14.3 | ||
IHg (ng/mL) | 101 | 101 | 0.12 | 0.24 | 0.33 | 0.46 | 0.86 | ||
(ng/g) | 101 | 101 | 0.11 | 0.24 | 0.32 | 0.44 | 0.82 | ||
ICPMS | THg (ng/g) | 397 | 397 | 1.94 | 3.15 | 4.66 | 6.90 | 13.2 |
Certified Values (Acceptable Range) (ng/mL) | I: LC-CVAFS (ng/mL) | C: LC-ICP-MS (ng/mL) | A: GC-ECD (ng/g) | CVAAS (ng/g) | ||
---|---|---|---|---|---|---|
Mean (SD) | Mean (SD) | Mean (SD) | Mean (SD) | |||
Seronorm, Whole blood L2 a | MeHg | 1.27 (0.76–1.77) | 1.46 (0.14) | |||
IHg | 14.6 (0.47) | |||||
THg | 17.0 (13.6–20.4) | 16.1 (0.60) c | I: 17.0 (0.38) e | |||
Quebec, human blood, PC-B-M1201 b | MeHg | 5.11 (0.26) | 5.47 (0.07) | 5.27(0.05) e | ||
IHg | 4.62 (0.05) | 4.99 (0.09) | ||||
THg | 9.47 (7.04–11.89) d | 9.73 (0.23) c | 10.5 (0.12) c | A: 8.79 (0.03) e I: 9.17 (0.09) e | ||
Quebec, human blood, PC-B-M1203 b | MeHg | 1.20 (0.17) | 1.32 (0.04) | 1.20 (0.02) e | ||
IHg | 0.94 (0.15) | 1.14 (0.03) | ||||
THg | 2.37 (1.73–3.01) d | 2.14 (0.04) c | 2.47 (0.03) c | A: 2.33 (0.05) e I: 2.44 (0.05) e | ||
Pooled human blood | MeHg | 9.46 (0.55) | 9.34 (0.31) | 8.47 (0.16) e | ||
IHg | 0.36 (0.12) | 0.39 (0.03) | ||||
THg | 9.81 (0.43) c | 9.73 (0.30) c | A: 8.97 (0.09) e I: 9.29 (0.09) e 9.73 (0.09) f |
Authors | Year | Samples | Methods | DL/MDL (ng/mL) | Sample Volume (μL) | Pretreatment |
---|---|---|---|---|---|---|
Our study | 2021 | Whole blood | LC-CVAFS | 0.12 (MeHg) | 250 | Acid digestion and sonication |
0.14 (IHg) | ||||||
LC-ICPMS | 0.04 (MeHg) | 200 | ||||
0.02 (IHg) | ||||||
Sogame et al. | 2019 | Whole blood | LC-ICPMS | 0.04 (MeHg) 0.02 (IHg) | 200 | Acid digestion and sonication |
Rodrigues et al. | 2010 | Whole blood | LC-ICPMS | 0.10 (MeHg) 0.15(EtHg) 0.25(IHg) | 250 | Sonication |
de Souza et al. | 2013 | Plasma | LC-CV-ICPMS | 0.004(MeHg) 0.005 (EtHg) 0.012(IHg) | 250 | Sonication |
Baxter et al. | 2011 | Serum | GC-ID-ICPMS | 0.03 (MeHg) | 2000 | Solvent extraction and derivatization |
Brombach et al. | 2015 | Urine | LC-CVAFS | 0.0015 (MeHg) | Microwave | |
Dórea et al. | 2011 | Hair | GC-CVAFS | 0.5 ng/g (MeHg) 1 ng/g (EtHg) | 20 mg | Acid digestion |
Wiseman et al. | 2019 | Whole blood | ID-SPME-GC-ICP-MS | 0.16 (MeHg) 0.13 (IHg) | 100 | TMAH digestion (20 h) and derivatization |
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Iwai-Shimada, M.; Kobayashi, Y.; Isobe, T.; Nakayama, S.F.; Sekiyama, M.; Taniguchi, Y.; Yamazaki, S.; Michikawa, T.; Oda, M.; Mitsubuchi, H.; et al. Comparison of Simultaneous Quantitative Analysis of Methylmercury and Inorganic Mercury in Cord Blood Using LC-ICP-MS and LC-CVAFS: The Pilot Study of the Japan Environment and Children’s Study. Toxics 2021, 9, 82. https://doi.org/10.3390/toxics9040082
Iwai-Shimada M, Kobayashi Y, Isobe T, Nakayama SF, Sekiyama M, Taniguchi Y, Yamazaki S, Michikawa T, Oda M, Mitsubuchi H, et al. Comparison of Simultaneous Quantitative Analysis of Methylmercury and Inorganic Mercury in Cord Blood Using LC-ICP-MS and LC-CVAFS: The Pilot Study of the Japan Environment and Children’s Study. Toxics. 2021; 9(4):82. https://doi.org/10.3390/toxics9040082
Chicago/Turabian StyleIwai-Shimada, Miyuki, Yayoi Kobayashi, Tomohiko Isobe, Shoji F. Nakayama, Makiko Sekiyama, Yu Taniguchi, Shin Yamazaki, Takehiro Michikawa, Masako Oda, Hiroshi Mitsubuchi, and et al. 2021. "Comparison of Simultaneous Quantitative Analysis of Methylmercury and Inorganic Mercury in Cord Blood Using LC-ICP-MS and LC-CVAFS: The Pilot Study of the Japan Environment and Children’s Study" Toxics 9, no. 4: 82. https://doi.org/10.3390/toxics9040082