title: Kinetic determination of thiocyanate on the basis of its catalytic effect on the oxidation of methylene blue with potassium bromate.
abstract: This study reports a sensitive kinetic spectrophotometric method for the determination of trace amounts of thiocyanate. In acidic solution, Methylene Blue (MB) is oxidized by bromate to form a colorless compound. The reaction is accelerated by trace amounts of thiocyanate and can be followed by measuring the absorbance at 664 nm. The absorbance of the reaction decreased with an increase in the reaction time. Under the optimum experimental conditions (0.56 M of sulfuric acid, 3.9 x 10(-5) M of MB, 3.0 x 10(-3) M of bromate, 180 s, 25 degrees C), thiocyanate can be determined in the range 5.0 - 180 ng/ml. The relative standard deviations (n = 8) are 2.81 and 1.43% for 10.0 and 150 ng/ml thiocyanate, respectively. The detection limit of this method is (3sigma) 3.8 ng/ml. This method was successfully applied to the determination of thiocyanate in real samples.
authors.affiliation: Department of Chemistry, Islamic Azad University (Yazd), Yazd, 89195-155, Iran. shishehbore47@yahoo.com
authors.forename: Masoud Reza
authors.initials: MR
authors.lastname: Shishehbore
authors.forename: Navid
authors.initials: N
authors.lastname: Nasirizadeh
authors.forename: Ali Asghar
authors.initials: AA
authors.lastname: Kerdegari
mesh_terms: D001959:Bromates / Q000737:chemistry* / Q000378:metabolism; D002384:Catalysis; D007700:Kinetics; D008751:Methylene Blue / Q000737:chemistry* / Q000378:metabolism; D010084:Oxidation-Reduction; D012680:Sensitivity and Specificity; D013053:Spectrophotometry; D013861:Thiocyanates / Q000032:analysis* / Q000737:chemistry
chemical_list: D001959:Bromates; D013861:Thiocyanates; C019536:potassium bromate; C031760:thiocyanate; D008751:Methylene Blue