Analytical and Bioanalytical Chemistry

, Volume 403, Issue 8, pp 2419–2428

Ultra-trace determination of mercury in river waters after online UV digestion of humic matter

Original Paper

DOI: 10.1007/s00216-012-5851-8

Cite this article as:
Leopold, K., Zierhut, A. & Huber, J. Anal Bioanal Chem (2012) 403: 2419. doi:10.1007/s00216-012-5851-8

Abstract

A fully automated online ultraviolet (UV) digestion method for subsequent mercury (Hg) quantification in humic matter containing river waters is reported. The new developed flow injection analysis system (FIAS) consists basically of a UV lamp, a meander-form quartz glass reaction tube for online irradiation of the sample, and a nano-gold collector for preconcentration of dissolved mercury species. The FIAS is coupled to an atomic fluorescence spectrometer (AFS) for Hg detection. The optimized procedure allows accurate mercury quantification in water samples with up to 15 mg C L−1 as dissolved organic carbon by addition of only 1% (v/v) of hydrogen peroxide solution and online UV irradiation for 6 min. Addition of strong oxidants and any other reagents is avoided due to the use of the catalytic active nano-gold collector. Here, preconcentration of Hg species, release of mercury as Hg0, and AFS measurement are performed without addition of any reagents. Hence, the proposed approach offers significant advantages over existing methods. Analytical figures of merit showed the good performance of the developed method: The limit of quantification was found to be as low as 0.14 ng Hg L−1. The linear working range is from 0.1 to 200 ng Hg L−1 and relative standard deviation is <6.0% (n = 9). The system was successfully validated by comparison of the mercury concentrations found in model and real water samples obtained by the reference method EPA 1631 and the proposed method. Furthermore, application to six real river waters confirmed the feasibility of the proposed approach.

Figure

Ultra-trace determination of mercury in river waters after online UV digestion of humic matter

Keywords

Mercury trace analysis Natural waters Humic matter Online digestion H2O2-assisted UV digestion Preconcentration Nano-gold collector Flow injection analysis 

Abbreviations

AFS

Atomic fluorescence spectrometry

C

Carrier

CV

Cold vapor

DOC

Dissolved organic carbon

EPA

Environmental protection agency

FIAS

Flow injection analysis system

GLS

Gas–liquid separator

ID

Inner diameter

NPOC

Non-particular organic carbon

OD

Outer diameter

P

Peristaltic pump

PET

Polyethylene terephthalate

S

Sample

SL

Sample loop

UPW

Ultra-pure water

UV

Ultraviolet

Supplementary material

216_2012_5851_MOESM1_ESM.pdf (188 kb)
ESM 1(PDF 187 kb)

Copyright information

© Springer-Verlag 2012

Authors and Affiliations

  1. 1.Institute of Analytical and Bioanalytical ChemistryUniversity of UlmUlmGermany
  2. 2.Arbeitskreis Analytische ChemieTechnische Universität MünchenGarchingGermany

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