Simultaneous determination of binary mixtures of sulfonylurea herbicides in water by first-derivative photochemically induced spectrofluorimetry

First-derivative photochemically induced spectrofluorimetry (PIF-D-1) is ap plied to the simultaneous determination of binary mixtures of 4 sulfonylure a herbicides in aqueous micellar samples. Synthetic binary mixtures of sulf orneturon-methyl with chlorsulfuron, metsulfuron-methyl, and 3-rimsulfuron, respectively, are well resolved by using the zero-crossing point procedure . PIF-D-1 allows the determination of binary mixtures of these herbicides w ith linear dynamic ranges over about 2 orders of magnitude, limits of detec tion between 0.5 and 52 ng/mL, and relative standard deviations within 0.3- 2.9%. Application to the determination of binary mixtures of these herbicid es in spiked tap water samples yielded satisfactory recoveries (90-117%).