Investigation of Fe(III) bonding properties of tetracaine using spectrofluorimetric method

Abstract

The metal bonding properties of tetracaine (TCN) were investigated by using spectrofluorimetric method. Fluorescence  quenching of TCN by Fe(III) was studied and optimal experimental conditions were determined. The excitation and emission wavelengths were l_ex= 306 nm and l_em= 373 nm for the Fe(III)-TCN complex in water medium. The calibration curve was obtained from Stern-Volmer equation plotting to F₀/F-[Fe³⁺] graphs and the linearity was found within the  range of  0.22-2.23mg.ml^-1 for the Fe(III)-TCN complex under optimal conditions. The detection limit (LOD) and the quantitation limits (LOQ) of the proposed method for this complex were 8.29 ng.ml^-1 and 27.60 ng.ml^-1 respectively. The stochiometry of  this complex was also determined by using the continuous variation method and the molar ratio of Fe(III)-TCN was calculated as 1:1. The interaction between the tetracaine in eye drop form and standard Fe(III) was investigated by applying this quenching method and obtained satisfactory results.