Fast Monitoring of Nano‐Molar Level of Gentamycin by Fast Fourier Transform Continuous Cyclic Voltammetry in Flowing Solution

Abstract

A novel method for the determination of gentamycin in flow‐injection systems has been developed in this work. The principal advantages of this method are that it is rapid, simple, and possesses low detection limit. Some investigations were also done to find the effects of various parameters on the sensitivity of the proposed method. The conditions producing the performance were the pH value of 2, the scan rate value of 350 V/s, accumulation potential of (100 mV), and accumulation time of 0.9 s. Some of the advantages of the proposed method are: the removal of oxygen from the test solution is not required anymore, the detection limit of the method is sub‐nanomolar, and finally, the method is fast enough for determination of such compounds, in a wide variety of chromatographic methods. We also introduce a special computer‐based numerical method for calculation of the analyte signal and noise reduction. After subtracting the background current from noise, the electrode response was calculated, based on partial and total charge exchanges at the electrode surface. The integration range of currents was set for all the potential scan ranges, including oxidation and reduction of the Au surface electrode, to obtain a sensitive determination. The waveform potential was continuously applied on an Au disk microelectrode (12.5 µm in radius). Detention limit of the method for gentamycin was found to be 1.0×10⁻⁹ M. For 10 runs, the relative standard deviation of the method at 1.0×10⁻⁷ M was 2.1%.

Keywords:

• Gentamycin
• flow injection
• continuous cyclic voltammetry
• flow injection analysis
• fast Fourier transformation

Acknowledgments

The authors thank the Tehran University Research Council for support of this work.