Ultratrace determination of mercury in water following EN and EPA standards using atomic fluorescence spectrometry

Abstract

Chemical vapour generation has been used in combination with atomic fluorescence spectrometry to determine mercury at ultratrace concentrations down to 0.1 ng L(-1). A time-based injection of 1 mL of solution for measurement was sufficient to generate a steady-state detector response in the direct mode of measurement. The detection limit calculated from a ten-point calibration curve according to DIN 32645 was 0.26 ng L(-1). Instrument noise is limited by reflected radiation from the light source rather than by the dark current of the photomultiplier. The detection limit is directly influenced by the reagent blank which was 2 ng L(-1) in the experiments described. Focusing by amalgamation and subsequent thermal desorption generates a detector response which is about eight times higher in peak intensity and about twice as large in integrated intensity. The detection limit under these conditions is 0.09 ng L(-1) which can be further improved by preconcentration of larger volumes of solution for measurement. The cycle time for one individual reading is about 40 s without amalgamation and 125 s with amalgamation. The linear dynamic range of the system is five orders of magnitude with a single photomultiplier gain setting. The carry-over is less than 0.3% in direct measurement mode. Reference water samples and a surface water containing approximately 5 ng L(-1) were used to prove the validity of the method for real samples. Good accuracy and recoveries of 103% were calculated using the fast direct determination technique.

Mesoporous Silica-gold Films for Straightforward, Highly Reproducible Monitoring of Mercury Traces in Water

“…In addition, to obtain highest sensitivity Hg(0) vapor can be pre-concentrated by the amalgamation technique (AT). Commercially available amalgamation traps are either made from silver- or gold- coated and [8] and silica wool [9] or consist of bulk materials like gold foil strips [10] and Au/Pt gauzes [11]. Coupling CV, AT, and atomic/mass spectrometry provides high sensitivity mercury detection with detection limits in the low pg·L −1 -range [12].…”

Solid‐phase preconcentration and determination of mercury(II) using activated carbon in drinking water by X‐ray fluorescence spectrometry

“…[3,4] Because of the extremely low levels of mercury in various matrices, e.g. the upper limit for total mercury concentration in drinking water recommended by the European Community is 1 mg l À1 , [5] highly sensitive and sophisticated analytical procedures are required for its determination; the most commonly used ones are cold vapor generation-atomic absorption spectrometry, [6,7] cold vapor generation-atomic fluorescence spectrometry, [8,9] and inductively coupled plasma mass spectrometry. [10] In addition, a preconcentration step has usually been needed for mercury determination in environmental samples.…”

Determination of Se, Pb, and Sb by atomic fluorescence spectrometry using a new flameless, dielectric barrier discharge atomizer

“…This design results from a number of considerations. It not only minimizes the background noise from the argon emission of the plasma, but also avoids the reflected radiation from the light source as found elsewhere [33]. In our primary studies, it was found that the sensitivity was poor without the use of a shield gas because of the reactions between the free atoms produced from the plasma and ambient air.…”