An ion chromatographic method for the separation and determination of As(III) empolying both constant and pulsed potential amperometric detection at platinum electrodes has been compared using cylindrical wire, thin layer, and wall‐jet flow cell detectors. Operational parameters such as limit of detection, linear dynamic range, stability, reproducibility, and flow rate dependence are reported for each detector cell. The different detector designs have features which make them individually appealing, depending on the type of application being considered and which operational parameter is most important. However, the limit of detection with the wall‐jet electrode of 1 × 10−9 M is superior to the other electrode designs (this may not necessarily be the case for other analytes) and makes this the preferred method for the determination of arsenic in bottled mineral water. Additionally, a lower limit of detection is achieved with constant potential amperometric detection than is the case with pulsed potential amperometric detection, which suggests that pulsed methods may not be advantageous for the detection of species at potentials where a large background current is exhibited at very positive potentials as required for the determination of arsenic.
- Flow detectors
- ion chromatography