The AULA 254 is used for fully automatic determination of mercury traces in liquid samples and sample digests. The instrument carries out routine analysis: sample after sample following exactly the preselected procedure thus increasing efficiency and productivity of your lab. Applications include:

 •   Water, waste water, soils and Effluents
 •   Applicable to EPA Methods: 245.1, 245.7, 1631, 7470 and 7471A
 •   Medicine (urine, blood, saliva, hair)
 •   Chemical industry (process monitoring, quality control)
 •   Geochemistry (geological and mineralogical samples)
 •   Petrochemistry
 •   Metallurgy and material testing

Reliable and proven method
The working principle of the system is based on the continuous flow method. First the mercury contained in the sample is transformed into the elemental state by addition of a reducing agent to the sample flow. In a cross-flow reactor the mercury is stripped with a gas stream and carried into the optical cell which is made entirely of fused silica. There the quantitative determination of mercury is obtained by measuring UV absorption at a wavelength of 253,7 nm at room temperature. This analytical technique is commonly known as cold vapor atomic absorption spectrometry (CVAAS), a method that has proved itself as extremely sensitive and selective over many years. No long purging or rinsing procedures even when samples with high concentrations are analyzed. The typical duration of a full measurement cycle is 80 ... 280 seconds. The quick screening mode allows performing analyses in even a shorter time

The AULA 254 can be equipped with an optional sample preparation system for aqueous samples. The digestion procedure derives from standard methods commonly used in the laboratory. The sample is automatically drawn from the auto-sampler vial and is continuously mixed with a strong oxidizing reagent (e.g. potassium permanganate, bromide-bromate). Subsequently the sample/oxidant mixture is heated to approx. 98 °C in a heated coil. After the oxidation step hydroxylamine hydrochloride and tin-(II)-chloride are added for reduction of mercury into the elemental state.