Synthesis of sulfonated naphthalene-formaldehyde condensates and their trace-analytical determination in wastewater and river water

Naphthalenesulfonates and their condensates with formaldehyde (SNFC) are wi dely used in industrial processes, e.g. as plasticizers for concrete or as tanning agents. Based on their high aqueous solubility these compounds are expected to be eliminated incompletely in mechanical-biological treatment p lants and to end up in the aquatic environment. Due to the lack of referenc e compounds the identification and quantification of these condensates in t he aquatic environment was impossible in the past. This paper describes the synthesis of several condensates of 2-naphthalenesulfonate with formaldehy de. With the synthesized products as reference compounds it was possible fo r the first time to detect and quantify some sulfonated naphthalene-formald ehyde condensates in the aquatic environment. For this purpose characterist ic peaks in the HPLC screening of wastewater and river water samples were c ompared with the corresponding peaks of a technical SNFC product. Three out of several paths on which these compounds enter the aquatic environment we re identified. The identified compounds in the analyzed wastewater samples have concentrations between 0.14 and 110 mu g/L.