663 VA Stand for Metrohm Autolab potentiostats

I perform the electrochemical method of phase-sensitive ac-voltammetry (PSACV) measurements with µ-Autolab (Eco Chemie) connected with 663 VA Stand (Hg) Electrode (Metrohm). This electrochemical method (including electrochemical system) of PSACV is a unique, and reproducible method for monitoring and studying adsorption processes of ecologically important organic matter with surface active properties-SAS. An Ag/AgCl (NaCl) as a reference, static Hg drop (SMDE) as working, and Pt as counter electrodes is used. Measurements are based on the SAS adsorption effect at the surface of the SMDE, in the natural samples and 0.55 M NaCl as the model electrolyte solution at a potential of −0.6 V (vs. Ag/AgCl electrode) and accumulation times (15-120s) with stirring. Preparing the sample for measurement is very simple. The original, 'fresh' sample can be measured or it can be filtered, thereby obtaining even more informations simply and in a short time. By filtration through a GF/F filter, the total SAS from the original sample is divided into particulate and dissolved fractions. In addition to measuring the amount of SAS in the sample, it is also possible to monitor the effects of adsorption at the electrode surface and get an initial insight into the structure of the substances in the analyzed sample. For example, the different response in the original and filtered sample or the different response in the original and acidified sample can be monitored. Furthermore, by monitoring the shape of the desorption waves of the voltammograms, it is possible to determine the prevailing type of organic material in relation to the model substances. The µ-Autolab instrument is generally easy to use and provides fast, reproducible, and reliable measurement results. Also, the maintenance of the instrument is not so expensive or demanding compared to some other more sofisticated instrumentation. With this instrument, it is possible to perform several electroanalytical analyses in the same aliquot (etc. trace metals, sulfur species). Also, I like Gpes softwere which is very intuitive and easy to use. In combination with HTCO disolved organic carbon (DOC) measurements, PSACV becomes powerful methodology for DOC reactivitiy assesment.

Review Date: 12 Dec 2022 | Metrohm AG