ROOM TEMPERATURE-PHOSPHORESCENCE OF INDOLE-3-BUTYRIC ACID IN MICELLAR SYSTEM OF TWEEN-40

Room temperature-phosphorescence of indole-3-butyric acid (IBA) in micellar system of non-ionic surfactant Tween-40 was studied in detail and used as a sensitive method for determination of IBA.In this particular case,iodide (added as solid KI) was found to be a suitable heavy atomic perturber,and dilute sodium sulfite solution was added to remove oxygen in the test solution.The excitation wavelength and the emission wavelength of the phosphorescence were found at 281 nm and 446 nm respectively.Linear relationship was held between intensity of phosphorescence and concentration of indole-3-butyric acid in the range of 8.0×10-8-2.0×10-6mol·L-1,with a detection limit of 7.0×10-9mol·L-1.Presence of organic solvents in the reaction system was undesirable,quenching of phosphorescence in different degree was observed by ethanol,ethyl ether,acetonitrile and acetone.In its application to the analysis of some water and soil samples,RSD′s of less than 3.0% were obtained,and recoveries found were in the range of 95.2% to 104.0%.