Abstract: The method of indirect electrochemical detection accompanied with liquid chromatography (Indirect LCEC) was applied to separate and determine the non-electroactive esters containing methyl formate, ethyl formate, methyl acetate and ethyl acetate.It was shown that the peak current was linear in the range of 3.2×10^-9-4.4×10^-8mol, 2.4× 10^-9-2.8×10^-8 mol, 2.0×10^-9-4.0×10^-8 mol and 2.2×10^-9-2.4×10^-8 mol for these four compounds, respectively.The relative standard deviation of eight parallel determination is 0.89 %.The method was applied to determine the concentration of methyl formate in waste water, the recovery was in the range of 97% to 108%.The mechanism of indirect electrochemical detection of non-electroactive species is also discussed.The indirect electrochemical approach greatly expands the usage of electrochemical method, so that a variety of non-electroactive species can also been determined.

Key words: Indirect LCEC, Non-electroactive species, Mobile phase additive, Determination of ester