Analysis of river water and drinking water from seven European countries.

During the months of June to August and September to December 1972 and again from January to April 1973, the river and drinking water at a number of points in seven European countries was examined for fluorescent content. The purpose of the river water studies was to identify any traces of fluorescent whitening agents (FWAs) and relate them as far as possible to knolementary role and also helped to interpret the scatter of the control level of the river water studies. Identification and separation were carried out by means of a combination of spectrofluorimetry and thin layer chromatography. Detection limits and reproducibility of the methods of determination are explained in the chapters V/3-7 (methods of analysis for FWAs. The second river water survey showed that at only one sampling point (Borås in Sweden) there was detectable concentrations (up to 8 ppb) of a lipophilic unsulfonated FWA [2, 5-BIS (BENZOXAZOL-2-YL)THIOPHENE], And these were still about 1 ppb in the third survey. JENSEN and co-worker had previously detected this substance at the same location. No traces of FWAs were detected in any of the other tests. The detection limit in river water was 0.01 ppb (1 part per American billion = 10(-3) gram per metric ton). For identification purposes, a test mixture of six FWAs each with a different chemical constitution and different fields of application was used, and this was first exposed to light in an aqueous solution for some minutes.