Sub-Second Accumulation and Stripping for Pico-Level Monitoring of Amikacin Sulphate by Fast Fourier Transform Cyclic Voltammetry at a Gold Microelectrode in Flow-Injection Systems

A novel chemiluminogenic reagent, refered to as spiro form fluorescein hydrazide, was synthesized, and its application to chemiluminescence (CL) determination of Co²⁺ is described. The method is based on the catalytic effect of Co²⁺ on the autoxidation of sulfite in basic solution to generate a series of powerful oxidative intermediates, which then oxidize colorless, nonfluoresent fluorescein hydrazide to generate strong CL emission. The CL signal is linearly related to the concentration of Co²⁺ in the range of 0.1–200nM with a detection limit of 0.04nM. The optimal conditions for the detection of Co²⁺ were evaluated, and the possible CL mechanism is discussed. The proposed method has been applied to the determination of Co²⁺ in pharmaceutical preparations and in soil samples.