Flow and batch systems for copper(II) potentiometric sensing

A new carbon paste electrode modified with tetramethyl thiuram disulfide is prepared to use as copper potentiometric sensor in batch and flow analysis. The influence of pH and carbon paste composition on the potentiometric response is studied. The principal parameters of the flow system are optimized and the detection limits and the selectivity coefficients of the potentiometric sensor are calculated for static and flow mode. In both cases, the sensor shows high selectivity to copper ions but in flow analysis this selectivity is higher. The obtained detection limits are 4.6 × 10⁻⁸ M for batch measurements and 2.0 × 10⁻⁷ M for on-line analysis. The potentiometric sensor is applied to copper(II) determination in real samples in static and flow measurements. In both analysis modes, successful results are obtained.