title: Selective and eco-friendly method for determination of mercury(II) ions in aqueous samples using an on-line AuNPs-PDMS composite microfluidic device/ICP-MS system.
abstract: In this study we developed an on-line, eco-friendly, and highly selective method using a gold nanoparticle (AuNP)-coated polydimethylsiloxane (PDMS) composite microfluidic (MF) chip coupled to inductively coupled plasma mass spectrometry (ICP-MS) to separate trace Hg(2+) ions from aqueous samples. Because Hg(2+) ions interact with AuNPs to form Hg-Au complexes, we were able to separate Hg(2+) ions from aqueous samples. We prepared the AuNPs-PDMS composite through in situ synthesis using a PDMS cross-linking agent to both reduce and embed AuNPs onto PDMS microchannels so that no additional reductants were required for either AuNP synthesis or the PDMS surface modification (2% HAuCl4, room temperature, 48 h). To optimize the proposed on-line system, we investigated several factors that influenced the separation of Hg(2+) ions in the AuNPs-PDMS/MF, including adsorption pH, adsorption and elution flow rates, microchannel length, and interferences from coexisting ions. Under optimized conditions (pH 6.0; adsorption/elution flow rates: 0.05/0.5 mL min(-1); channel length: 840 mm), we evaluated the accuracy of the system using a standard addition method; the measured values had agreements of ≥ 93.0% with certified values obtained for Hg(2+) ions. The relative standard deviations of the proposed method ranged from 2.24% to 6.21%. The limit of detection for Hg(2+) for the proposed on-line AuNPs-PDMS/MF/ICP-MS analytical method was as low as 0.07 µg L(-1).
authors: Graduate Institute of Medicine, Kaohsiung Medical University, Kaohsiung 80708, Taiwan.
authors: Keng-Chang
authors: KC
authors: Hsu
authors: Department of Medical Laboratory Science and Biotechnology, Kaohsiung Medical University, Kaohsiung 80708, Taiwan.
authors: Cheng-Fa
authors: CF
authors: Lee
authors: Department of Medical Laboratory Science and Biotechnology, Fooyin University, Kaohsiung 80708, Taiwan.
authors: Wei-Chang
authors: WC
authors: Tseng
authors: Department of Public Health, College of Health Science, Kaohsiung Medical University, Kaohsiung 80708, Taiwan.
authors: Yu-Ying
authors: YY
authors: Chao
authors: Graduate Institute of Medicine, Kaohsiung Medical University, Kaohsiung 80708, Taiwan; Department of Medical Laboratory Science and Biotechnology, Kaohsiung Medical University, Kaohsiung 80708, Taiwan; Center of Excellence for Environmental Medicine, Kaohsiung Medical University, Kaohsiung 80708, Taiwan. Electronic address: yelihu@kmu.edu.tw.
authors: Yeou-Lih
authors: YL
authors: Huang
mesh_terms: D000327:Adsorption; D004129:Dimethylpolysiloxanes / Q000737:chemistry*; D006046:Gold / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D007477:Ions / Q000032:analysis / Q000737:chemistry; D013058:Mass Spectrometry / Q000379:methods*; D008628:Mercury / Q000032:analysis* / Q000737:chemistry; D053768:Metal Nanoparticles / Q000737:chemistry*; D046210:Microfluidic Analytical Techniques / Q000379:methods*; D015203:Reproducibility of Results; D014874:Water Pollutants, Chemical / Q000032:analysis* / Q000737:chemistry
chemical_list: D004129:Dimethylpolysiloxanes; D007477:Ions; D014874:Water Pollutants, Chemical; C013830:baysilon; D006046:Gold; D008628:Mercury
keywords: Gold nanoparticle; Inductively coupled plasma mass spectrometry; Mercury; Microfluidics; Polydimethylsiloxane