Analytical Sciences


Abstract − Analytical Sciences, 20(7), 1013 (2004).

Direct Fluorescence Quantification of Chromium(VI) in Wastewater with Organic Nanoparticles Sensor
Leyu WANG, Lun WANG, Tingting XIA, Ling DONG, Guirong BIAN, and Hongqi CHEN
College of Chemistry and Materials Science, Anhui Normal University, Wuhu 241000, China
Under ultrasonic irradiation, organic fluorescence nanoparticles have been prepared by a reprecipitation method. Compared with single organic fluorophores, these nanoparticles are brighter, more stable against photobleaching and more water-soluble. They also have high room-temperature fluorescence quantum yields (∼20%) and a long fluorescence lifetime (∼0.2 µs). Based on the fluorescence quenching of nanoparticles by chromium(VI), a method for the selective determination of chromium(VI) without the separation of chromium(III) in water was developed. Under the optimal conditions, the linear range of the calibration curve was 7.0 × 10-6 - 1.0 × 10-4 mol L-1. The detection limit was 2.8 × 10-6 mol L-1. The method is characterized by a short reaction time, stable fluorescence signals, simplicity and high selectivity. The present assay has been applied to the selective quantification of Cr(VI) in wastewater with satisfactory results.