This method requires a preliminary test to eliminate any samples which contain less than 50 ng/l PAH. For samples containing higher concentrations, a quantitative determination according to W-010.06.120 Quantitative Determination of Polycyclic Aromatic Hydrocarbons (PAH) in Drinking Water must be performed.
Drinking water intended for use in beer brewing as well as in the production of other foods
The analysis is conducted by means of HPLC. The analytical interest in polycyclic aromatic hydrocarbons can be attributed to emissions into the environment of these toxic, partially carcinogenic substances from various sources. Polycyclic aromatic hydrocarbons (PAH) exist in almost all waters, both dissolved in water and in the undissolved form, usually adsorbed onto solids (sediments, particulate matter). Distinguishing between undissolved and dissolved PAH, which can be desirable for the analysis of surface waters and wastewater, is not carried out in the analysis of drinking water.
The Trinkwasserverordnung – TrinkwV (the regulations governing drinking water in Germany) requires that the following five polycyclic aromatic hydrocarbons be quantified:
Benzo-(b)-fluoroanthene
Benzo-(ghi)-perylene
Benzo-(a)-pyrene
Benzo-(k)-fluoroanthene
Indeno-(1,2,3-cd)-pyrene
The PAH compounds are concentrated through extraction with cyclohexane and evaporation. The separation is carried out by means of high-performance thin-layer chromatography. The results are evaluated through examination under UV light, followed by comparison of the Rf values with the reference substances.