[Back]

E. Margui, P. Kregsamer, M. Hidalgo, J. Tapias, I. Queralt, C. Streli:
"Analytical approaches for Hg determination in wastewater samples by means of total reflection X-ray fluorescence spectrometry";
Talanta, 82 (2010), 821 - 827.

At present, there is a considerable interest in Hg monitoring in wastewater samples due to its widespread
occurrence and the high toxicity of most of its compounds. Hg determination in water samples by means
of total reflection X-ray fluorescence spectrometry (TXRF) entails some difficulties due to the high vapor
pressure and low boiling point of this element that produce evaporation and loss of Hg from the surface
of the reflector during the drying process, commonly used for sample preparation in TXRF analysis.
The main goal of the present research was to develop a fast and simple chemical strategy to avoid
Hg volatilization during the analysis of wastewater samples by TXRF spectrometry. Three different analytical
procedures were tested for this purpose: (i) increasing the viscosity of the wastewater sample
by adding a non-ionic surfactant (Triton® X-114), (ii) Hg immobilization on the quartz reflectors using
the extractant tri-isobutylphosphine (Cyanex 471X) and (iii) formation of a stable and non-volatile Hg
complex into the wastewater sample. The best analytical strategy was found to be the formation of a Hg
complex with thiourea (pH = 10) before the deposition of 10 L of sample on the reflector for following
TXRF analysis. Analytical figures of merit such as linearity, limits of detection, accuracy and precision
were carefully evaluated. Finally, the developed methodology was applied for the determination of Hg
in different types of wastewater samples (industrial effluents, municipal effluents from conventional
systems and municipal effluents from constructed wetlands).

Hg, TXRF, Wastewater samples

http://dx.doi.org/10.1016/j.talanta.2010.05.066

http://publik.tuwien.ac.at/files/PubDat_188570.pdf