Report No DWI0058

Aug 1986


Most of the organic material in drinking and other water samples and many pollutants and potential pollutants are non-volatile. Little is known of the composition of this non-volatile fraction because of the lack of suitable analytical techniques and information is urgently needed on the nature of these components. The methods previously developed for analysis of non-volatiles (WRc Report DoE 385-M) have been further refined and applied to a range of drinking water, river and effluent samples. A complementary approach to broad survey analysis, namely 'target compound' analysis, has been developed for analysis of specific non-volatile compounds including particular pesticides, pharmaceuticals and fish farm chemicals.

Procedures for the isolation of non-volatile organic substances from a variety of water samples have been developed using XAD-resin sorption/solvent extraction, freeze drying/solvent extraction, adsorption onto Sep-Pak cartridges and sublation. HPLC methods were developed and used to separate and fractionate extracts of water samples prior to identification of the separated compounds using mass spectrometry. The use of coupled-column HPLC considerably improved the resolution of the complex mixtures of non-volatiles isolated compared to separation on a single column. A coupled-column reversed-phase microbore HPLC system has been developed and an on-line pre-column enrichment system designed and successfully used for microbore HPLC fractionation of water extracts. The improved HPLC separation facilitated examination of HPLC fractions by field desorption and fast atom bombardment mass spectrometry.

Among the non-volatile organics identified using the survey and 'target compound' approaches were polychlorinated terphenyls, surfactants, pharmaceuticals, pesticides, epoxy resin constituents and fish farm chemicals. Sublation extracts from river and drinking water and industrial and sewage effluents have been examined by fast atom bombardment mass spectrometry. Many non-ionic, cationic and anionic surfactants have been identified. The majority of the identified non-volatile organics were anthropogenic in origin.

An assessment was made of the suitability of two LC-MS systems for the analysis of non-volatile organics isolated from water samples. Authentic non-volatile organics and extracts of drinking water and industrial effluents were examined using these techniques and encouraging results obtained.

Methods for isolating, separating, concentrating and analysing non-volatiles in water samples have been devised, developed and assessed. Using these techniques a significant number of novel non-volatiles have been identified. Such techniques would be ap plicable to many other non-volatile chemicals if they were thought to be significant. However, in this work only a small proportion of the non-volatiles present in water have been identified. Identification of the remainder requires more widespread application of techniques, described in this report and new techniques, particularly LC-MS.

Copies of this report may be available as an Acrobat pdf download under the 'Pre 2000 Reports' heading on the DWI website.