Online mercury analyser HZ-ASF100(Hg)

Measurement principle

Mercury is measured after total digestion. Ionic mercury in acidic solution is then reduced by a reducing agent, producing atomic mercury in the solid state. After equilibration, the mercury vapour is expelled from the reaction vessel by passing the sample through an efficient gas/liquid separator and purging with high-purity argon gas. The Hg is transferred into an inert gas stream that carries the liberated Hg (0) to the chamber of a cold vapour atomic fluorescence spectrometer (CVAFS) for detection. The concentration of Hg is determined by atomic fluorescence spectrometry at 253.7 nm. Quality is assured by calibration and evaluation of the oxidation, purge, and detection systems. No interferences are observed from transition metals (Fe²⁺, Iron³⁺, Zinc²⁺, With²⁺, No²⁺, Lead and Chromium³⁺and elements that form hydrides (If⁴⁺, Sb³⁺ and As³⁺).

Product features

Extended average time between fill/empty/replacement operationsunattended operating time is improved by the presence of a gas-saving device and low-temperature storage of the reducing agent. The mean time between maintenance activities is effectively prolonged by the dual-position design of the lamp, through switching the light source.

Accurate resultsAdopting the recommended international standard method based on cold vapour atomic fluorescence, the detection results are highly compatible with the laboratory method.

Extremely low detection limitThe indirect method utilising cold vapour technique allows for very sensitive detection of mercury with minimal background. The superior signal-to-noise ratio of the atomic fluorescence method allows for detection and quantification limits in the sub-μg/L range.

High adaptabilitythanks to the integrated automatic digestion module, the analyser is highly adaptable to a wide range of water samples, characterised by varying water quality.