Capillary Electrophoresis Detection of Hydrogen Peroxide by Using Titanium Ion and 4-(2-thiazolylazo)resorcinol

A novel method for the detection of hydrogen peroxide in aqueous solution was developed via reaction between H₂O₂, trivalent titanium ion (Ti³⁺) and 4-(2-thiazolylazo) resorcinol (TAR), resulting in a ternary complex with a maximum UV absorbance at 530 nm. The CE detection of H₂O₂ was fast, sensitive and cost-effective without pretreatment procedures. H₂O₂ was detected within 15 min at 1 to 100 µM range with the lowest detection limit at 1.0 µM. Under the optimized CE conditions, the concentration of H₂O₂ in coffee or tea extract was quantitatively determined. Our results show that CE detection of the ternary complex of H₂O₂-Ti³⁺-TAR has potential applications for the detection of H2O2 in aqueous sources.