Development of a Simple and Low-cost Device for Fluorometric Determination of Selenium in Water Samples

A portable spectrofluorometer device comprising an ultraviolet LED (380 nm) as a light source, an LED driver, a microsyringe as a cell, an optical fiber cable, a CCD spectrometer and a personal computer was used on-site. The device works on a battery for 3 h without the need to re-charge. The consumptions of reagents and sample solution can be reduced by using the device. Using fluorescein solution as a standard, the performance of this device was compared with that of a bench-top spectrofluorometer. The device applicability was demonstrated by the determination of selenium content in river water as a model of hazardous elements in the environment. Selenium reacted with 2,3-diaminonaphthalene to form piazselenol, which was then extracted with cyclohexane. The determination was carried out with both the portable device and the spectrofluorometer. The entire process was completed in approximately 15 min. The recovery of selenium in a river-water sample ranged from 104 – 112% and the detection limit was 0.5 µg L–1.