Abstract: Hexadecyltrimethylammonium bromide (CTAB) modified clay electrode was made. The electrochemical behavior of paraquat (PQ) was studied by cyclic voltammetry and the results indicated that the process was controlled by diffusion. The important electrochemical parameters including the effective area of CTAB NaMM-CMC/GCE Aeff=2.108mm2, and the diffusion coefficient D=5.73×10-4cm2/s were calculated. Determination parameters were optimized and the correlation between peak current and concentration was studied by square wave stripping voltammetry (SWSV). From the results we can find a good linearity between the peak current and concentration of PQ in the range of 9.660×10-7~3.865×10-4 mol/L, and its detect limitation was 3.297×10–7 mol/L. The content of PQ in real water was detected with SWSV and the spiked recovery rate for ipa1 was between 94.55% and 108.25%.

Key words: electrochemical behavior, Montmorillonite, CTAB, Paraquat, Square wave stripping voltammetry