Time-resolved fluorometry in detection of ultratrace polycyclic aromatic hydrocarbons in lake waters by liquid chromatography

Abstract

For determination of polycyclic aromatic hydrocarbons in natural lake waters at ultratrace levels, a time-resolved fluorescence measurement system was developed. By replacing the Xe lamp of a conventional fluorometer with a N/sub 2/ laser-pumped dye laser as an excitation source, the authors could improve the detection capability for polycyclic aromatic hydrocarbons by 1 to 2 orders of magnitude. The measurement system was used as a detector for high-performance liquid chromatography. A detection limit of 180 fg was achieved for benzo(a)pyrene. The measurement precision was 3.9%. The instrument was applied to measure polycyclic aromatic hydrocarbons in the water of Lake Mashu. After allowing for extraction efficiency, the authors obtained analytical results of 0.009 ng/L, 0.007 ng/L, and 0.014 ng/L for benzo(k)fluoranthene, benzo(a)pyrene, and benzo(ghi)perylene, respectively. 9 figures, 7 tables.