The applicability of commercial screen-printed gold electrodes (SPGEs) for the determination of Hg(II) in
ambient water samples by square wave anodic stripping voltammetry has been demonstrated. Electrode
conditioning procedures, chemical and instrumental variables have been optimized to develop a reliable
method capable of measuring dissolved mercury in the low ng mL−1 range (detection limit 1.1 ng mL−1),
useful for pollution monitoring or screening purposes. The proposed method was tested with the NIST
1641d Mercury in Water Standard Reference Material (recoveries 90.0–110%) and the NCS ZC 76303 Mercury
in Water Certified Reference Material (recoveries 82.5–90.6%). Waste water samples from industrial
origin and fortified rain water samples were assayed for mercury by the proposed method and by a reference
ICP-MS method, with good agreement. Screen printing technology thus opens a useful way for
the construction of reliable electrochemical sensors for decentralized or even field Hg(II) testing.