Bioassay-Directed Fractionation of the Organic Extract of SRM 1649 Urban Air Particulate Matter

Abstract

Separation of 2 grams of the methylene chloride extract of NIST SRM 1649 (Washington, D.C. urban air particulate matter) into six compound class fractions by acid-base partitioning and silica gel column chromatography is demonstrated here. Recoveries of organic mass and Salmonella typhimurium TA98 mutagenic activity were greater than 80%. The fractionation method showed reproducible distribution of both mass and mutagenic activity; the compound class mass distribution results were similar to those obtained for more typical analytical fractionation of a milligram quantity of the extract mass. The most polar compound class fractions contained the greatest proportions of mutagenic activity.