Methylmercury and Inorganic Mercury in Cord Blood Using

Overview

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Key numbers

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90–115% determined by reference material analysis. To evaluate the reliability of 366 cord blood
median (5th–95th percentile) concentrations of MeHg and IHg were 5.4 (1.9–15) and 0.33 (0.12–0.86)
and LC-CVAFS. The median cord blood:maternal blood ratios of MeHg and IHg were 1.3 and 0.5,
N = 325 Mercury speciation analysis using LC-
low. A standard solution of methylmercury chloride (1000 mg/L) was obtained from Alfa
Aesar (Ward Hill, MA, USA). Standard solutions of mercury (II) chloride (1000 mg/L)
0.25 mL of 7% (v/v) hydrochloric acid solution containing 1.5% (w/v) L-cysteinea and
The instrument settings for LC-ICP-MS are shown in Table 1.
The instrument settings for LC-ICP-MS are shown in Table 1.
Table 1. Instrument setting for LC-CVAFS and LC-ICP-MS.
Reductant 2% tin (II) chloride in 10% hydrochloric acid, 4.5 mL/min
Valve switching mode 3–8.7 min: 0.08% (w/v) sodium tetrahydroborate (100%)
Option gas (20% O2 in Ar) 5%
A standard solution of methylmercury chloride (1000 mg/L) was obtained from Alfa
Aesar. Standard solutions of mercury (II) chloride (1000 mg/L) were obtained from Kanto
was generated by dilution with 7% (v/v) hydrochloric acid solution containing 1.5% (w/v)
L-cysteine. Concentrations used to generate the calibration curve ranged from 0.397 to
nominal concentrations. The pretreatment solution was 7% (v/v) hydrochloric acid solution
containing 1.5% (w/v) L-cysteine. Blood samples (0.25 mL) were placed and weighted in
Thereafter, 10% trichloroacetic acid was added and mixed using a vortex mixer. The tube
instrument settings for LC-CVAFS are shown in Table 1.
concentration in the calibration curve, according to Currie et al. (18) (Table 2). The following
Table 2. Method detection limit (MDL) calculation.
(Table 3); relative standard deviation (RSD) was less than 10% in inter-day and intra-day.
homogeneity was confirmed by analyzing some elements (Table S4). The pooled blood
LC-CVAFS analyses were within 102–111% and 90–115%, respectively (Tables S2 and S3).
Table 3. Reproducibility: repeated measurements of standard middle concentration (ng/mL).
RSD Total (%) 5.2
RSD Total (%) 5.4
RSD Total (%) 2.8
RSD Total (%) 4.0
centiles are shown in Table 4. The correlations for each mercury concentration were assessed
assessed using the non-parametric Wilcoxon Signed Rank (Table 5). p < 0.05 was considered
Table 4. Concentrations of methylmercury and inorganic mercury in blood samples from the Japan Environment and
Table 5. Interlaboratory comparison of the concentrations of methylmercury, inorganic mercury, Japan Environment and
manual of the Ministry of Environment of Japan (2004). f ICP-MS results (see Table S4).
MeHg and IHg. MeHg was detected in all samples by LC-ICP-MS. The median (5th–95th
vided by Sero AS and the Institute National de Santé Publique du Québec (Table 5). Wil-
Québec (Table 5).MeHg and
and MeHg. The median (25th–75th
GC-ICP-MS and applied it to recent immigrant women (N = 76). Our method was applied
Table 6. Summary of speciation mercury analysis of biological samples.

Methods (brief)

LC-ICP-MS and LC-CVAFS: The Pilot Study of the Japan
LC-ICP-MS and LC-CVAFS: The Pilot Health, Kitakyushu 807-8555, Japan; rei-suga@med.uoeh-u.ac.jp (R.S.); shimono@med.uoeh-u.ac.jp (M.S.)
Received: 16 March 2021 liquid chromatography-inductively coupled plasma-mass spectrometry (LC-ICP-MS) and liquid
chromatography-cold vapor atomic fluorescence spectrometry (LC-CVAFS). The validated LC-ICP-
MS method was applied to 101 maternal blood and 366 cord blood samples in the pilot study of the
Japan Environment and Children’s Study (JECS). The accuracy of the LC-CVAFS method ranged
samples, fifty cord blood samples were randomly selected and analyzed using LC-CVAFS. The
cord blood. Inter-laboratory comparison showed a relatively good agreement between LC-ICP-MS
and LC-CVAFS. The median cord blood:maternal blood ratios of MeHg and IHg were 1.3 and 0.5,
distributed under the terms and CVAFS; ICP-MS
coupled plasma mass spectrometry (ICP-MS) or using LC (or GC) coupled with cold vapor
atomic fluorescence spectrometry (CVAFS) (9–13).
Children’s Study (JECS) (14). When analyzing 100,000 pairs of samples from mothers and
of a sample, has high sensitivity, and involves simple pretreatment. Therefore, this study
method’s reliability using LC-ICP-MS, we performed an inter-laboratory comparison of
MeHg and IHg measurements in blood using LC-ICP-MS and LC-CVAFS. Furthermore,
453 participants who provided consent, maternal whole blood and cord blood samples
were collected in the second to third trimester and at birth, respectively. Mean (standard

Implications

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Update history

The five most recent substantive edits to this page, classified major (evidence or structure moved), correction (a published value or statement was wrong and has been fixed), or minor (narrative rewritten without changing the underlying evidence). Each description is derived from what the edit did to this page; the linked commit is the authoritative record, routine regeneration passes are excluded, and the full version history lives in git. When DOI minting comes online (see schema docs), each entry below will also link to a version-pinned DataCite DOI.

Commit	Date	Change	Description
b01ec52c	2026-08-04	major	2 sections added
d49e450f	2026-08-03	major	5 sections added; narrative text revised