Potentiometric detection in liquid chromatographic systems: An overview

Analytical techniques are extensively used in various fields of human activity to define quality and usage safety patterns of goods and consumables. Between those, liquid chromatography is probably the most common, generally combined with optical detectors. Alternatively, electroanalytical techniques provide versatile tools that offer high selectivity and sensitivity in a short time, using simple and low cost instrumentation. Amperometric, coulometric and conductimetric detectors are thus well established in HPLC with commercially available instrumentation. Despite sharing some of the stated features, the use of potentiometric detectors seems however overlooked. Potentiometry with ion-selective electrodes has been highlighted in both batch and flow analysis systems, evidenced by numerous applications performed worldwide. The determination of electrolytes in blood samples, heavy metals in natural water samples and pharmaceutical drugs in bulk drug materials are some of the representative examples. The developments achieved so far in hydrodynamic separation systems proved the great potential of potentiometry to become a competitive detection technique with the many others. Therefore, it is intended to present an overview about potentiometric detection in liquid chromatography with the purpose of enhance its importance for future analytical applications.