Dissolved minerals and trace elements, i.e., cations (such as K, Ca, Na, Mg, Fe, Cu, Zn, Mn) play a role in beer production and product quality that should not be underestimated. For example, this group is necessary for yeast growth and thus for the fermentation process. In addition, however, excessive concentrations, especially of heavy metals, can have very detrimental effects on the stability and sensory properties of the beer. Therefore, control within the framework of brewing technology must be considered essential. Elements such as potassium and magnesium are also important for human nutrition. However, the usual determination methods of gravimetry, complexometry and colorimetry are usually too inaccurate, cumbersome or time-consuming for this purpose. Atomic absorption spectrophotometry is an elegant, fast and very accurate analytical method.
The cations in beer and wort are determined with this analysis.
This method is suitable for both wort and beer.
Inductively coupled plasma optical emission spectroscopy (ICP-OES) is a fast and reliable method for the laboratory analysis of metals. Inductively coupled plasma (ICP), a high frequency field of ionized gas, serves as a medium for atomizing and exciting the substances found in samples. Liquid, dissolved or aerosol samples are injected into the ionized gas stream. In emission spectroscopy, ICP can be used in conjunction with a number of optical and electronic systems either simultaneously or sequentially in multi-element spectrometers. In the plasma, the atoms and ions are excited to a higher energy state bringing about the emission of electromagnetic radiation (light), primarily in the ultraviolet and visible region of the spectrum. Metals ordinarily occur as ions in the temperature range typical for ICP of 6000 to 10000 K; however, non-metals and metalloids are only partially ionized.
ICP-OES operates within a very wide range. This usually encompasses six orders of magnitude in concentrations smaller than μg/l up to g/l, depending upon the element and the concentrations used for the set of analysis data. With ICP-OES, beer and wort can also be analyzed without prior processing of the samples, in contrast to AAS. Methods for determining the following in beer and wort will be described below: Al, B, Ba, Ca, Co, Cu, Fe, K, Mg, Mn, Mo, Na, P, Si, Sr, Sn and Zn.