The analysis of EDTA (ethylenediaminetetraacetic acid) in water by HPLC

Abstract niet beschikbaarThis report describes the development of a method for the determination of ethylenediaminetetraacetic aced (EDTA) in various types of water at low mug/L level. After a short sample pretreatment the sample is analyzed using reversedphase ion-pair liquid chromatography. UV absorbance detection is applied at 254 nm. The method is suitable to determine EDTA in surface water, bank filtrate, infiltrated water and fineshed drinking water. The method is simple (short sample pretreatment) and has a low limit of detection (0.8 mug/L). In general, the method provides calibration curves which have good regression characteristics (correlation coefficient > 0.999). 31 samples from several drinking water companies have been analyzed in order to determine the concentration of EDTA.DGM/DWL-

The optimization of a method for the analysis of ditalloq-dimethyl- ammoniumchloride (DTDMAC) in water

This report describes the optimization of a method for the analysis of DTDMAC in water. After a short sample pre-treatment, the sample is injected in a HPLC-system. After separation, ion-pair formation takes place between DTDMAC and DAS, which is a fluorophore. Detection is performed fluorometrically. The method is suitable for the determination of DTDMAC in surface water, bank filtrate, infiltrated water and finished drinking water. The method is simple and sensitive (1.1 mug/L) ; the accuracy is not ideal.DGM/DWB-

The occurrence and behaviour of ditallow-dimethyl-ammoniumchloride (DTDMAC) during drinking water production

Cationic quaternary ammonium compounds are used as fabric softeners. DTDMAC, a technical product with an ecotoxicological risk for aquatic organisms, is the most well known. Ecotoxicological risk values have been determined, followed by an agreement to ban the product from fabric softeners. The quaternary ammonium compounds are highly adsorptive for anionic surfactants, particles and sediments in watersystems. This report describes research on occurrence and behaviour of DTDMAC during drinking water production and gives possible risks for public health. DTDMAC occurs in raw surface water (maximum 30 mug/l), in bankfiltrate (maximum 5 mug/l) and in finished drinking water (maximum 4.3 mug/l ; median 1.7 mug/l). The measured concentrations in drinking water do not give risks for public health. The maximum acceptable value, calculated on the basis of literature data is 0.8 mg/kg food or water. On every sampling point only two measurements were carried out, and therefore effects due to the purification processes can only be interpreted qualitatively. In general, a relatively high concentration of DTDMAC can be decreased easily (bottom passage, conventional purification steps) to a few mug's, but the compound cannot be removed completely even by ozone or activated carbon filtration. In surface water the concentrations are much higher than the negligible risk value (0.5 mug/l) for aquatic ecosystems. The actual concentration given in this report give no reason to continue the research into the meaning of DTDMAC for drinking water supplies.DGM/DWB-