Our previous work determined the As(III) concentration using coupled SI/ASV and in-situ Au film modified on SPCE [29]. However, the limit of detection was insufficient for quantitative As detection in environmental analysis. On the one hand, renewal of the Au-film was limited by the amount of Au on the electrode surface; a large amount of Au resulted in incomplete cleaning. The previous work showed that it was possible to renew the Au-film SPCE in situ. On the other hand, a large amount of Au on the SPCE led to an increase in roughness and surface area, which allows for a lower As detection limit. The current study, therefore, presents a different solution for the determination of the inorganic As concentration using SI/ASV with an Au-modified SPCE. The experiments were performed under simple test conditions to maintain the lifetime of the modified Au on the SPCE without the need for the renewal process. A large linear range between 1 and 100 μg L1 was achieved and the lowest value of the detection limit (3S/N) obtained was 0.03 μg L1. The proposed method was successful in assessing the As concentration in the real water samples.