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 manganesetetrasulfonatophthalocyanine (MnTSPc) has been applied to the determination of hydrogen peroxide in marine surface water samples. As MnTSPc was used as a substitute for horse radish peroxidase, the difficulties caused by possible loss of enzyme activity over time was eliminated. 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 ions 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).