A novel quantitative electroanalysis method, triple potential step amperometry (TPSA), was developed and explained with an example of nitrobenzene analyzing in water. The selectivity of TPSA was im- proved by controlling the potential step within a narrow interval and using enzyme-modified electrode, the narrow potential step makes the method avoid most interferents, and enzyme-modified electrode can enhance the response of target substance selectively. The peak area was investigated for quanti- tative calibration, such as nitrobenzene concentration showing a linear relation with the peak area, with the correlation coefficients being 0.9995. The t-test and F-test were applied to evaluating the reliability of TPSA, the results showed that there was no evidence of systematic error for TPSA, and the method was of no significant difference from CV. The merit of fast detecting and few potential changing times make the TPSA suitably applicable to low-cost automatic monitoring equipments.
