L. Nitschke

A technique to study the electrochemistry of minerals

Recently a new technique has been introduced to study the dectrochemistry of metals and alloys [1,2]. This socal led abrasive stripping voltammetry comprises a mechanical (abrasive) transfer of traces of the solid material onto the surface of a solid electrode and the following electrochemical oxidation or reduction of these traces with an appropriate measuring method (e.g., differential pulse voitammetry). It turned out that this technique is highly useful to study the electrochemistry of sparingly soluble salts, including a great variety of minerals. This method opens up new areas of research, not only because of the extreme fastness of measurements (including sample preparation) but also because of the superior quality of the voltammograms and the trace amounts of material (less than 1/tg) which are sufficient to perform the study. To know the electrochemistry of minerals is important for a deep understanding of the formation and transformation of minerals. It is not less important for a possible electrochemical metallurgy [3]. Last, but not at least, abrasive stripping voltammetry can develop toward an easy method for mineral identification [4] even in fieldwork. As an example the electrochemistry of the mineral boulangerite, PbsSb4SI1 (Neumtihle, Greiz, GDR) will be discussed here. This mineral belongs to the extensive group of sulfo-salt minerals [5]. Figure 1 depicts the differential pulse voltammograms obtained after abrasive transfer of trace amounts of the mineral onto the surface of a paraffine-impregnated graphite electrode. Curve A is the cathodic voltammogram with the reduction of boulangerite according to

Identification of solid materials with a new electrochemical technique — the abrasive stripping analysis

SummaryA new technique for the characterization of solid materials is proposed, consisting in the transfer of extremely small amounts of the solid substance by abrasion onto the surface of a suitable solid electrode. The abrased material is electrochemically stripped off and this process is traced with a voltammetric method, e.g., differential pulse voltammetry. The method allows the easy and fast identification of solid materials, avoids the dissolution of the sample and hence reveals information about the structure of the solid material, thus allowing electrochemical phase analysis. The proposed technique of abrasive stripping analysis is applicable to a wide range of inorganic and organic substances.

Abrasive stripping voltammetry — the electrochemical spectroscopy for solid state: application for mineral analysis

SummaryAbrasive stripping voltammetry possesses several features of a spectroscopy. It allows the qualitative and quantitative analysis of electroactive solid materials. This work is focussed on the application for the unambiguous identification of minerals (sulphides, sulfo-salt minerals, fahlores). μg-amounts of a mineral are sufficient to perform a series of measurements. Three different voltammetric modes were used to study the electrochemical behaviour of the minerals.

Fast and non-destructive identification of dental alloys by abrasive stripping voltammetry

SummaryThe non-destructive and fast identification of dental alloys (amalgams and nickel alloys) by abrasive stripping voltammetry is described. The method is applicable for dental and forensic purposes. The voltammograms also reveal important information on corrosion stability of these alloys. Thus abrasive stripping voltammetry is an analytical express method to assess corrosion stability of dental alloys.

A simple and convenient solid state microanalytical technique for identification and characterization of the high temperature superconductor YBa2Cu3O7−x

SummaryThe application of a new electroanalytical technique, abrasive stripping voltammetry, is described for the purpose of identification and characterization of orthorhombic YBa2Cu3O7−x. The method is based on the peculiar property of this compound that the copper ions therein cannot be reduced below the +1 oxidation state, whereas all other copper compounds exhibit this property. The total analysis takes about 2 min and is very reliable.

Differential staircase voltammetry - A new electroanalytical technique

SummaryA new voltammetric method is described, which uses a staircase ramp and measures the current during two small time intervals at the end of every potential step. The difference between these two currents is amplified and recorded. The obtained data suggest that the proposed method of differential staircase voltammetry is as sensitive as differential pulse voltammetry.