Pierre M. Bersier

Tutorial review. Advanced electroanalytical techniques versus atomic absorption spectrometry, inductively coupled plasma atomic emission spectrometry and inductively coupled plasma mass spectrometry in environmental analysis

The challenge for the chemical industry in the 1990s and beyond is: (i) innovation and profitability, and (ii) environmental protection and safety. This is also true for analyses in which the needs are for simple, reliable and viable techniques. Analyses are costly, running costs especially can be very high. There are still too many poor quality analyses. The task of the analytical chemist is to choose the most appropriate procedure in order that the desired information about the particular material of interest can be provided. The pros and cons of advanced electroanalytical techniques versus modern atomic absorption spectrometric, inductively coupled plasma atomic emission spectrometric and inductively coupled plasma mass spectrometric methods commonly in use in industrial and technical laboratories are discussed. The features that make electroanalytical methods competitive techniques are: the very large useful concentration range (from 1 to 10–10 mol l–1 and less for inorganic, organometallic and organic species), the larger linear ranges than many commonly used instrumental techniques, the ability to assay dissolved and solid samples, the ability to speciate on the basis of complex lability and to distinguish between different states of valency, and the immunity of the matrix to samples with high ionic content, etc. These are illustrated by practical examples in this work. However, the still limited commercial availability of highly automated electroanalytical instrumentation is a serious limitation for the large-scale routine use of these methods in the industrial and control laboratory.

Electrochemical reduction of nitrogen-flourine Bonds: relevance to the reactivity of electrophilic flourinating agents

Abstract The cyclovoltammetric and polarographic behaviour of nitrogen-flourine bond containing compounds, including representative electrophilic flourinating agents is described. The reduction potentials are strongly affected by the substituents on the nitrogen atom and by the electrode material. All reductions are irreversible on the investigated time scale. The influence of these results on the reactivity of electrophilic flourinating agents is discussed.

Polarography, voltammetry and tensammetry: tools for day-to-day analysis in the industrial laboratory

Selected practical inorganic and organic applications of modern polarography, voltammetry and tensammetry to real problems from fields as diverse as high technology (stereolithography), organic synthesis and environmental protection and environmental analysis serve to illustrate the vast area of application of these techniques in the industrial and technical laboratory.

Applied Polarography and Voltammetry of Organic Compounds in Pratical Day-To-Day Analysis Part II

In organic chemistry, polarography and voltammetry are most frequently applied for the solution of (1) practical, mainly analytical, problems. To show the scope and possibilities of these techniques in the analysis of dyes, agricultrual products, plastics, and pharmaceutical materials we shall briefly, and in a nonexhaustive way, discuss some practical examples. Polarography can also be used for (2) the solution of electrochemical problems, and (3) to provide useful information on fundamental problems of organic chemistry such as determination of equilibrium constants, and rate constants for fast (t,1/2 <0.5 sec) and slow (T,1/2 < 10 sec) reactions, detection of intermediates, etc. The reproducibility of polarographic measurements (about 3%) allows obtaining of kinetic data with a precision comparable to that of most other methods used in reactions kinetics. Because applications of the types (2) and (3) have been covered in sufficient detail elsewhere,136, 195, 345, 346 we shall restrict our discussion to...

High Catalytic Activity of Rosindone and Related Compounds in Alkaline Pulping

Abstract The efficacies of phenazine, phenazone and rosindone derivatives as additives in alkaline pulping were investigated and compared. Phenazones and rosindones are superior to the phenazines described earlier. Equimolar charges of rosindone sulfonate stabilize carbohydrates more than anthraquinone (vM∼l.l) but the de-lignification effect is slightly inferior (rM = 0.72). Due to low solubility rosindone does not follow the square root relationship. Low rosindone charges (<0.1%) catalyze delignification as efficiently as anthraquinone (rM ∼1). The half-wave potentials (pH Ik, 90°C, IN NaOH, SCE, in the presence of wood) were measured. No correlation is to be found between pulping efficacies (rM-value) and redox potentials (Ey2). The differences of the pulping efficacies are mainly explained in terms of chemical stability.

Quantitative and qualitative analysis of saframycins. Polarographic and voltammetric behaviour and direct polarographic determination of saframycin A in fermentation broth and the high-performance liquid chromatographic determination of various saframycins

The polarographic and voltammetric behaviour of various saframycins has been studied. The scope and limitations of their individual and simultaneous determination and the direct determination of saframycin A in fermentation broth, as compared with results obtained using an HPLC method which allows separation of complex mixtures, are discussed.

Monitoring and assay of water treatment additives by alternating current tensammetry and voltammetry: scope and limitations

The alternating current (a.c.) tensammetric behaviour of different commercially available water treatment additives is described. Possibilities and limitations of their routine determination by a.c. tensammetry at low levels (0.5–10 ppm) in different aqueous media are discussed. Indirect differential-pulse voltammetry via the 12-molybdophosphate derivative allows a classification between phosphino-containing and phosphorus-free water treatment compounds. Practical examples are given.

Applications of Electrometric Techniques in Wood Chemistry

Abstract A review is given of the application and limitations of potentiometric and potentiostatic (polarographic and voltammetric) studies. Quantitative determinations of pulp-relevant systems (liquors) and compounds (sulfur and lignin compounds; guinoid and non-quinoid additives) at ambient and mid-range temperature (90 ± 10°C) as well as under soda pulping conditions are described. A specially developed pressure cell for the elucidation of the fate and mechanism of additives at temperatures up to 150 C is presented.

Applied Polarography and Voltammetry in Day-to-Day Environmental Analysis, Possibilities and Limitations

”The natural resources of the earth including the air, water, land, flora and fauna and especially representative samples of natural ecosystems must be safeguarded for the benefit of present and future generations through careful planning or management, as appropriate”.1