title: Flow injection kinetic spectrophotometric method for the determination of trace amounts of nitrite.
abstract: In this work, a new, simple and sensitive flow injection catalytic kinetic spectrophotometric determination of nitrite is reported based on catalytic effect of nitrite on the redox reaction between sulfonazo III and potassium bromate in acidic media. The reaction was monitored by measuring the decrease in the absorbance of sulfunazo III at 570 nm. Various chemical (such as the effect of acidity, reagents concentrations) and instrumental parameters (flow rate, reaction coil length, injection volume and temperature) were studied and were optimized. Under the optimum conditions calibration graph was linear in the nitrite concentration ranges of 8.00 x 10(-3)-3.00 x 10(-1) microg/ml (with slope of 2.40) and 3.50 x 10(-1)-1.80 microg/ml (with slope of 0.42). The detection limit was 6.00 x 10(-3) microg/ml of nitrite, the relative standard deviation (n=10) was 1.25% and 0.88% for 5.00 x 10(-2) and 2.00 x 10(-1)microg/ml of nitrite respectively. About 60 samples in 1h can be analyzed. The interfering effects of various chemical species were studied. The method was successfully applied in the determination of nitrite in food and environmental samples.
authors.affiliation: Department of Chemistry, Faculty of Science, Zanjan University, Zanjan, 45195-313, Iran. s.nouroozi@gmail.com
authors.forename: Siavash
authors.initials: S
authors.lastname: Nouroozi
authors.forename: Razieh
authors.initials: R
authors.lastname: Mirshafian
mesh_terms: D001391:Azo Compounds / Q000737:chemistry; D001959:Bromates / Q000737:chemistry; D002138:Calibration; D002384:Catalysis; D017022:Flow Injection Analysis / Q000379:methods*; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008461:Meat Products / Q000032:analysis; D009573:Nitrites / Q000032:analysis* / Q000737:chemistry; D010084:Oxidation-Reduction; D013053:Spectrophotometry / Q000379:methods*; D014867:Water / Q000737:chemistry
chemical_list: D001391:Azo Compounds; D001959:Bromates; D009573:Nitrites; C019536:potassium bromate; D014867:Water; C014836:sulfonazo III