AbstractThe use of chelating agent‐modified Nafion®‐coated mercury‐film electrodes (CNCMFEs) in square wave anodic stripping voltammetry (SWASV) for the determination of trace metals is described. The CNCMFE containing appropriate amounts of dimethylglyoxime (DMG) was applied for the determination of Ni(II), Cd(II), and Cu(II). A similar system that contains 2,2′‐bipyridyl (Bpy) was used for the determination of Pb(II). The effect of various model organic substances on the CNCMFEs in SWASV is thoroughly explored. The CNCMFEs are considerably more resistant to organic interferences than the Nafion®‐coated MFE. The implications of these interferences for the reliability and feasibility of stripping measurements using the CNCMFEs in real samples are discussed. Results presented for real samples demonstrate the analytical utility of the CNC