Submicron silica spheres decorated with silver nanoparticles as a new effective sorbent for inorganic mercury in surface waters.
An analytical method using silica supported silver nanoparticles as a novel sorbent for the enrichment and determination of inorganic mercury (iHg) in surface water samples has been developed. Silver nanoparticles (AgNPs) were synthesized by a completely green procedure and were deposited onto the amine functionalized surface of silica submicrospheres (SiO2-NH2). The prepared nanocomposite material (SiO2/AgNPs) was characterized by transmission electron microscopy, UV-vis spectroscopy, X-ray diffraction and atomic force microscopy. The sorption and desorption characteristics of the nanosorbent SiO2/AgNPs toward Hg species were investigated by a batch method. An excellent separation of iHg and methylHg was achieved in 20 minutes at pH 2. The high selectivity of the SiO2/AgNPs toward iHg was explained by Hg(ii) reduction and subsequent silver-mercury amalgam formation. The analytical procedure for the enrichment and determination of inorganic mercury in surface waters was developed based on solid phase extraction and ICP-MS measurements. The total Hg content was determined after water sample mineralization. The recoveries reached for iHg in different surface waters e.g. river and Black sea water samples varied from 96-101%. The limits of quantification are 0.002 μg L(-1) and 0.004 μg L(-1) for iHg and total Hg, respectively; the relative standard deviations varied in the ranges of 5-9% and 6-11% for iHg and total Hg, respectively, for Hg content from 0.005 to 0.2 μg L(-1). The accuracy of the procedure developed for total Hg determination was confirmed by a comparative analysis of surface river (ICP-MS) and sea (CV AFS) waters.
Department of Analytical Chemistry, Faculty of Chemistry and Pharmacy, University of Sofia, Bulgaria.
Tanya
T
Yordanova
Penka
P
Vasileva
Irina
I
Karadjova
Diana
D
Nihtianova
D004784:Environmental Monitoring / Q000379:methods; D057230:Limit of Detection; D013058:Mass Spectrometry / Q000379:methods; D008628:Mercury / Q000032:analysis* / Q000302:isolation & purification; D053768:Metal Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D045483:Rivers / Q000737:chemistry; D012623:Seawater / Q000032:analysis; D012822:Silicon Dioxide / Q000737:chemistry*; D012834:Silver / Q000737:chemistry*; D052616:Solid Phase Extraction / Q000379:methods; D014874:Water Pollutants, Chemical / Q000032:analysis* / Q000302:isolation & purification
D014874:Water Pollutants, Chemical; D012834:Silver; D012822:Silicon Dioxide; D008628:Mercury