Measurement of As(III) with in situ subtraction of background and interferent signals by double potential step-anodic stripping coulometry

An electrochemical instrument for the analysis of heavy metals in water via anodic stripping coulometry for applications in remote sensing.

“…A reduction potential of -600 mV vs. Ag/AgCl was found necessary over the -500 mV vs. Ag/AgCl employed previously [36] to ensure 100% deposition of As(III), which differs from the E 0 of 35 mV vs. Ag/AgCl. Previously, a large overpotential has been necessary for As(III) to ensure complete deposition on a gold electrode as a more negative potential is needed to achieve higher As(0) coverage because of As(0) metalloid properties and increased resistance [66,67].…”

“…The use of DPS-ASC for the analysis of As(III) in a thin-layer cell was explored by Marei et al [36]. This work evaluated the DPS-ASC method for the in situ background-corrected detection of As(III) in standard solutions, solutions containing interferent metals, and samples of Ohio River water.…”

“…Our research group has been focused on the electrochemical detection of species in thin-layer volumes for the past decade [33][34][35][36][37]. These microfluidic devices have been created using microfabrication techniques such as stamp-and-stick and photolithography.…”

“…Most recently, Marei et al developed a novel method termed double potential step-anodic stripping coulometry (DPS-ASC) [36]. DPS-ASC is a specific coulometric technique in which a series of potentials is applied to perform in situ background correction.…”

“…DPS-ASC was used to detect As(III) at 100 ppb levels in the electrochemical device equipped with a gold macroelectrode previously by our group [36], and the work was further expanded in Chapter II by increasing the volume up to 6.8 µL to reach a 20 ppb detection limit [68]. However, the WHO safety guideline is 10 ppb for As [20].…”