A pressure msensltlve sohd state reference electrode was prepared for m-situ voltammetnc measurements m lake water m conjunction with a submersible flow-through cell The dependence of the measured electrode potential on apphed pressure, temperature, and the nature and concentration of the electrolyte solution IS reported Reverslblhty tests (cychc measurements of the current as a function of apphed potentlal) provided a quahtatlve mdlcatlon of the state of the electrode Its hfetlme IS approximately two weeks, but electrodes are easdy prepared and can be stored for several months before use The electrode was also successfully used for voltammetnc measurements (differential pulse, square wave and hnear sweep voltammetry) m the laboratory Keywords Voltammetry, Sohd state reference electrode, Waters
Voltammetric measurements are particularly suitable for determuung metal concentrations m lake water due to the posslblhty of multi-element analysis and to their sensltlvlty However, measurement of metal concentrations m the nanomolar range and lower 1s generally hampered by contammatlons during sampling or sample handlmg before its analysis In addition, due to the change m condltlons during sampling (temperature, pressure, light), the sample often undergoes chemical changes such as degassmg of, or contamination by, O,, CO,, and/or H,S resulting m changes m pH or redox condltlons, and in the correspondmg changes m the speclatlon of many compounds or elements
In-situ voltammetrlc measurements usmg an immersible flow-through cell can overcome these problems [l] However,