Determination of trace cobalt(Ⅱ) in water sample by high sensitivity catalytical kinetic spectrophotometric method

摘要

A new catalytic kinetic spectrophotometric method for the determination of trace amount of cobalt(Ⅱ) in microemulsion medium has been developed. This method is based on the catalytic effect of cobalt(Ⅱ) on the hydrogen peroxide(H2O2) oxidation of hydroxyphenyl fluorone (DBH-PF) in the presence of cetyltrimethylammonium bromide (CTMAB) microemulsion medium and NaOH medium. All the variables were studied in order to optimize the reaction conditions. Beer's law is obeyed over the range of 0～0.12 ng/mL and the detection limit is 4.86×10-13 g/mL. The method has been successfully applied in determination of Co(Ⅱ) in water sample with satisfactory results.