Investigations On The Spectrofluorimetric Methods For The Determination Of Boron And Carbaryl In Environmental Samples

Spectrofluorimetry and the sequential injection system combined with fluorimetric detection were used in environmental analysis in this thesis. The methods were successfully applied to the determination of the available boron in soil samples and the carbaryl in environmental water samples.The first section of this thesis focused on the introduction of the basic knowledge of spectrofluorimetry and the application of the new technique of spectrofluorimetry in environmental analysis.In the second section, a sequential injection (SI) method coupled with fluorimetric detection was developed for the determination of the available boron in soil samples. This method is based on the formation of boron (B) complex with 1,8-dihydroxy naphthalene-3, 6-disulfonic acid (CA) in acidic media by fluorimetric detection (λex=319 nm andλem=373 nm). The calibration curve was rectilinear from 5.0 to 1000 ng/mL and the detection limit was 3.0 ng/mL. A sample throughput of 30 samples per hour and relative standard deviation of 0.77%(at 20 ng/mL level, n=11) were achieved. The proposed method was simple, rapid and sensitive, and successfully applied to the determination of the available boron in soil samples with the recovery in the range 90%-110%.In the third section, a simple, rapid and sensitive spectrofluorimetry was developed for the determination of carbaryl. This method is based on the fluorescence characteristic of carbaryl in acidic media by fluorimetric detection (λex=280 nm andλem=334 nm). The calibration curve was rectilinear from 3.2 to 144 ng/mL and the detection limit was 1.4 ng/mL. The relative standard deviation of 1.7%(at 9.6 ng/mL level, n=11) was achieved. The proposed method was successfully applied to the determination of carbaryl in environmental water samples with the recovery in the range 90%-110%.