Water intended for use as an ingredient in the production of beer (brewing liquor) or other foods
The nickel content is determined by employing a flameless method which utilizes graphite furnace atomic absorption spectrophotometry. This technique is suitable for determining the nickel content of water with very little nickel contamination. Any matrix effects can be eliminated by using the standard additions calibration technique.
An aliquot of the sample is dosed into a graphite tube and is subsequently subjected to a program comprising a three-step temperature regime through electrothermic resistance heating. As the temperature increases in each step, the consecutive steps include drying, matrix pyrolysis (incineration) and thermal dissociation into free atoms (atomization). These can be carried out separately. During the analysis, the graphite tube is under an inert gas atmosphere (argon).
Also important for graphite furnace AAS is background correction, which can be achieved using a continuum radiation source (deuterium) or through the Zeemann effect. Background correction with the Zeemann effect is used for particularly difficult sample matrices.
A hollow-cathode lamp usually serves as the light source.
Determination of the nickel content by means of spectrophotometry
Suitable for all types of wort, beer and beer-based beverages
After digestion of the sample, a complex is formed with dimethylglyoxime which is then measured photometrically.
Determination of the nickel content using an AAS graphite furnace
Suitable for all types of wort, beer and beer-based beverages
Nickel is measured using the flameless graphite furnace atomic absorption spectrometry. The determination is carried out at 232.0 nm. This process is well-suited for determining trace quantities of nickel in beer. Matrix effects, which may occur, are eliminated through the use of a standard addition calibration procedure. A palladium magnesium modifier reduces interference from compounds in the beer matrix.