Application of manganese-tetrasulfonatophthalocyanine as a new mimetic peroxidase in the determination of hydrogen peroxide in marine surface water samples with p-hydroxyphenylacetic acid as a substrate

The dimerization of p-hydroxyphenylacetic acid by hydrogen peroxide in the presence of manganese-tetrasulfonato-phthalocyanine (MnTSPc) has been appli ed to the determination of hydrogen peroxide in marine surface water sample s. As MnTSPc was used as a substitute for horse radish peroxidase, the diff iculties caused by possible loss of enzyme activity over time was eliminate d. An EDTA-Mn(II) solution containing 2.0x10(-3) mol/l EDTA and 1.0x10(-6) mol/l Mn(II) ion was used to reduce the interference caused by some metal i ons and to increase the sensitivity. The detection limit of the method is 6 .3x10(-8) mol/l. At a H2O2 concentration of 1.0x10(-6) mol/l, the standard deviation is 3.0% (n=6).