WATER-QUALITY CONTROL IN THE PRODUCTION OF DRINKING-WATER FROM RIVER WATER - THE APPLICATION OF IMMUNOLOGICAL TECHNIQUES FOR THE DETECTION OF CHLOROPHENOXY ACID HERBICIDES (2,4-D)
Ep. Meulenberg et Pg. Stoks, WATER-QUALITY CONTROL IN THE PRODUCTION OF DRINKING-WATER FROM RIVER WATER - THE APPLICATION OF IMMUNOLOGICAL TECHNIQUES FOR THE DETECTION OF CHLOROPHENOXY ACID HERBICIDES (2,4-D), Analytica chimica acta, 311(3), 1995, pp. 407-413
In the production of drinking water from river water, the quality of t
he raw water is extremely important. For this reason the Water Transpo
rt Company Rhine-Kennemerland (WRK) operates, among others, an early w
arning system. This system was found to be inappropriate for the detec
tion of certain chlorophenoxy herbicides (e.g., 2,4-D, MCPP, MCPA and
2,4-DP) that are occasionally found in the Rhine in increased levels (
above the drinking water norm of 0.1 mu g l(-1)). Commercially availab
le immunoassay kits were evaluated for use in pre-screening. With some
modifications to adapt the working range and to enhance the sensitivi
ty of the kits, they were found to be applicable in the early warning.
Comparison with a gas chromatography-mass spectrometry reference anal
ysis revealed no false negative results and a rate of false positive r
esults of about 10%. However, it should be taken into account that mat
rix effects may affect the results. A daily sampling frequency combine
d with an analysis frequency based on the actual flow in the river all
owed for a periodic batchwise analysis. This permitted a timely availa
bility of the results as well as a cost-effective use of the (modified
) kits.