Optimizing the Triple‐Potential Waveform for the Pulsed Amperometric Detection of Streptomycin

Abstract

A triple‐potential waveform used for amperometric detection of streptomycin (STP) is investigated. The mobile phase is an aqueous solution of 75 mM phosphoric acid. Waveform parameters are optimized to maximize the signal‐to‐noise ratio (S/N). The potentials of the waveform are designated E1, E2, and E3, and potentials are maintained for time periods t1, t2, and t3. Unlike the normal triple‐potential waveform, the cleaning function is accomplished at negative potential instead of positive potential in our triple‐potential waveform. The detection limit of STP is <0.04 µg mL⁻¹ (S/N=3). The linearity of STP ranges from 0.1 to 5 µg mL⁻¹ (r=0.9986). RSD (n=30) of the peak area of STP is 5.8%. The triple‐potential waveform shows low detection limits and long‐term reproducibility.

Keywords:

• Streptomycin
• antibiotics
• waveform
• pulsed amperometric
• HPLC

Acknowledgments

This project was supported by the Department of Health of GuangDong (NO.A2004074). All the experiments were performed in the Department of Community, Occupational, and Family Medicine, National University of Singapore. LCY is an attachment student of NUS. Dr. Lai is acknowledged for his valuable discussions.