Determination of the mutagen 3-nitrobenzanthrone in rainwater collected in Kyoto, Japan

The mutagen 3-nitrobenzanthrone was determined in rainwater. Rainwater was collected at a residential area in Kyoto, Japan. Organic matter containing 3-nitrobenzanthrone in rainwater was extracted using a 3M (St. Paul, MN, U.S.A.) Empore Extraction Disk C-18, and the extract was purified on a pyrenylethyl silylated silica gel column. The purified sample was then reduced using a platinum black column heated at 80degreesC. The reduced product of 3-nitrobenzanthrone, i.e. 3-aminobenzanthrone, was analyzed by normal-phase HPLC with fluorescence detection. 3-Nitrobenzanthrone in the rainwater was determined in the range of 0.07-2.6 ng l(-1). The concentration was higher from May to July and lower from October to December. 1-Nitropyrene was also determined by reversed-phase HPLC with fluorescence detection after platinum black column reduction. 1-Nitropyrene was detected in the range of 0.0056-0.19 ng l(-1), and this concentration range was lower than that of 3-nitrobenzanthrone.