Solvent extraction efficiencies of mutagenic components from diesel particles

In order to determine the efficiency of organic solvent extractions of fresh diesel-engine exhaust particles a series of Soxhlet extractions were set up using single and sequential extractions of fresh diesel particles with solvents of increasing polarities. Single extractions were carried out with methylene chloride, methanol, acetone and acetonitrile. A single filter was sequentially extracted with methylene chloride followed by methanol, acetone and acetonitrile. Methylene chloride extracted the most mutagenicity relative to the other three solvents. In addition, methylene chloride extracted 97% of the total extracted mutagenicity from a sequential series of extractions. Therefore, we conclude that of the solvents tested methylene chloride extracts the highest proportion of mutagens from fresh diesel exhaust and little mutagenicity is lost using methylene chloride as the only extraction solvent.