LIQUID-CHROMATOGRAPHIC DETERMINATION OF NORFLURAZON AND ITS INITIAL METABOLITE IN SOIL

A rapid, sensitive method for the determination of norflurazon in 4 so ils is described. Data on the initial soil metabolite is also obtained in soils with low organic matter. The method consists of extraction o f soil samples with methanol, filtration, liquid chromatographic separ ation of methanol-soluble components by using a C18 column, and fluore scence detection with excitation at 294 nm and emission measured at 39 8 nm. Recoveries from fortified soils were >90% for norflurazon and >8 0% for desmethylnorflurazon from the Shipps, Lexington, and Harkey soi ls. Average percent relative standard deviations over the soils examin ed was 5.5% for norflurazon and 8.7% for desmethylnorflurazon. The lim it of detection for norflurazon was 10 ng/g soil, whereas the limit of detection for desmethylnorflurazon was 100 ng/g soil because of its s maller relative detector response.