Carbon paste electrode with a wide anodic potential range

Abstract

spectrometer, as reported in the literature (5). The spectrometric resolution is about 1500 (10% valley), the total amount of the peak corresponding to -ionone is about 0.7 Mg (0.02% of the sample).In the scanning conditions described in the caption of Figure 5, this corresponds to about 10 nanograms of a-ionone to get the spectrum. Nevertheless, the spectrum is still very intense and the trace of the intermediate galvanometer is sufficient to unequivocally identify the compound.The spectrum of Figure 5 has been taken in routine work. Chromatographic efficiency and mass spectrometric sensitivity and resolution are both nearly as good as possible. The number of theoretical plates is about 6500.The possibility of using a wide range of flow rates is helpful for obtaining mass spectra of minor components in complex organic mixtures. In fact, columns of high loading capacity can be exploited. This allows the major peaks not to be overloaded and the minor ones to be present in sufficient amount to take interpretable mass spectra. The (5) K. Biemann, "Mass Spectrometry," Organic Chemical Applications, McGraw-Hill, New York, N.Y., 1962.main advantages of this system are that one can get mass spectra from a very complex chromatogram without the need of doing it at least twice, and that a very large range of linear gas velocities can be used without problems for the operating conditions of the mass spectrometer.

Carbon Paste Electrodes in Facts, Numbers, and Notes: A Review on the Occasion of the 50‐Years Jubilee of Carbon Paste in Electrochemistry and Electroanalysis

“…This section can be ended with another curiosity, which is a special treatment of graphite proposed by Lindquist [42]. In order to lower adsorption capabilities of graphite, he tried to remove adsorbed oxygen by heating in vacuum with subsequent stabilization by impregnating with a ceresin wax.…”

Stripping Voltammetric Determination of Iodide with Synergistic Accumulation at a Carbon Paste Electrode

“…In his report, a poor signal reproducibility of both I 2 and I ¹ was attributed again to a solubility of iodine in pasting liquid. Lindquist [22] demonstrated the extreme polarizability of a specially prepared CPE (up to þ1.85 V vs. SCE) on the oxidation of iodide to iodate (proceeding in several steps via elemental iodine and hypoiodate). Methods for the determination of iodide with CMCPEs utilize ion-pairing of the analyte with tetraalkylammonium [12,13] or cinchonine [14].…”

Wax-Impregnated Carbon Paste Electrode Modified with Mercuric Oxalate for the Simultaneous Determination of Heavy Metal Ions in Medicinal Plants and Ayurvedic Tablets

“…It was then heated to a high temperature to remove adsorbed oxygen. 21 This powder was added to an appropriate quantity of ceresin wax dissolved in warm n-hexane; 39 the mixture was placed in a water bath, stirred and heated till the n-hexane evaporated. For the preparation of the modified electrode, the modifier (mercuric oxalate) ranging from 6% to 18.37% (mass of the modifier to the total mass of the carbon paste) was prepared by weighing out an appropriate quantity of the modifier into an agate and grinding it thoroughly to get a fine powder.…”

“…Therefore, prior to preparing the paste, carbon powder is pretreated by heating at a high temperature, with subsequent impregnation of the pores by ceresin wax. 21 The rapid diffusion of heavy metals as environmental contaminations has called for attention to their determination at trace and ultra trace levels. 22,23 Such elements tend to concentrate in soil, biological and industrial samples.…”