A comparison of methods for concentrating mutagens in drinking water--recovery aspects and their implications for the chemical character of major unidentified mutagens.

A comparison of techniques for concentrating mutagenic compounds in drinking water has shown that XAD-2 adsorption and dichloromethane extraction have acceptable and almost identical enrichment properties, while purging at an elevated temperature is inappropriate in this context. Quantitatively, the most important drinking water mutagens could only be adsorbed (extracted) after acidification of the water, and even then recovery was far from complete. Recovery experiments with known mutagens from pulp mill effluents have shown that none of the major chlorination-stage mutagens identified thus far can explain the mutagenic activity of extracts from neutral or acidified chlorinated drinking water.