title: Solid phase extraction using a sulfoxide adsorbent for preconcentration and separation of Hg(II) in natural water followed by ICP-MS measurements.
abstract: A separation and preconcentration method based on solid-phase extraction using sulfoxide adsorbent was developed for the determination of Hg(II) in natural water samples by inductively coupled plasma mass spectrometry (ICP-MS).  The sulfoxide adsorbent was packed into a commercially available syringe-driven column (with a bed volume of 1.0 mL), which permitted off-line sample loading and on-line elution/measurement.  The optimized operating conditions were as follows: sample condition for Hg(II) adsorption, 0.5% HCl; sample-loading flow rate, 10 mL min(-1); eluent for recovering Hg(II), 1% cysteine water solution.  A test using multi-element mixed solution showed that most trace elements in natural water, except for Bi, could be completely separated from Hg(II).  The recoveries of Hg(II) were 99.0 ± 3.2 and 100.7 ± 4.3%, respectively, when 0.64 and 0.16 ng mL(-1) of Hg(II) were added into the test sample.  The detection limit of Hg(II) using a quadrupole ICP-MS after 10-fold preconcentration was 1.5 pg mL(-1).  The blank value was 2.8 ± 0.5 pg mL(-1).
authors.affiliation: National Metrology Institute of Japan, National Institute of Advanced Industrial Science and Technology, Tsukuba, Ibaraki, Japan. yb-zhu@aist.go.jp
authors.forename: Yanbei
authors.initials: Y
authors.lastname: Zhu
authors.forename: Ben
authors.initials: B
authors.lastname: Ahmady
authors.forename: Masahiko
authors.initials: M
authors.lastname: Numata
authors.forename: Koichi
authors.initials: K
authors.lastname: Chiba