This analysis describes the method for quantitatively determining the concentrations of polycyclic aromatic carbons in drinking water. Analytical methods using high performance, thin layer chromatography (HPTLC) and high performance liquid chromatography (HPLC) are suitable for this purpose.
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)-fluoranthene
benzo-(ghi)-perylene
benzo-(a)-pyrene
benzo-(k)-fluoranthene
indeno-(1,2,3-cd)-pyrene
Enrichment of the PAH is performed using solid phase extraction. The extract is obtained from the sample through separation with high performance liquid chromatography on the appropriate stationary phases under isocratic conditions. Detection is conducted with a fluorescence detector. The determination is quite sensitive because these polycyclic aromatic hydrocarbons possess substantial fluorescence properties. Since the fluorescence characteristics of these substances are substance-specific, they are determined using two spectra, the excitation and emission spectra. Thus, selective detection is possible. Through recognition of the specific spectra for each substance and the means of detection at the appropriate wavelengths, maximum sensitivity and selectivity are attainable.