The polarographic conditions used for the reduction of some derivatives of quinone on the dropping mercury electrode are herein described. The polarograms were obtained in partially aqueous media, using dimethylformamide as solvent, ammonium acetate as main electrolyte and gelation or Triton X-100 as maximum suppressor.By this method, concentrations as low as 0.1-0.5 mg/mL could be determined for each quinonic component. This practical work confirms that the larger the molecular masses, are the more negative the reduction electrochemical potentials of quinones are. This allows to conclude that not only the aminic groups on the anthraquinonic nucleus affect the electrochemical reduction potentials, but also that of the cyclic amplification of quinonic compounds might lead to different potentials. Due to these variations of the potential, selective and significant polarographic curves could be obtained.

The method is based on the reaction between carbon monoxide and the Pd(II)-p-nitrosodiphenylamine complex, in a medium containing hexamethylphosphotriamide. Two reduction processes take place in this reaction: Pd(II) is reduced to Pd(O), followed by reduction of nitroso group to amino, catalyzed by Pd(O). The reaction product is spectrally characterized by an intense absorption band in the ultraviolet range, with a maximum at 285 nm. This method can be applied for determining carbon monoxide from static gas mixtures, the lower sensitivity limit being 50 ppm, for a volume of air sample of 1L.

The method proposed for determining codeine, dionin and thebaine by differential pulse polarography is based on the reduction (in ammoniacal medium) of the nitroderivatives obtained by dissolving the substances in concentrated nitric acid. The values of the reduction potentials range between -0.45 and -0.69 V. Morphine and heroine do not interfere in the determination of the mentioned alkaloids.

The extraction of Ni2+ from aqueous solutions using Lix 64N solutions in various inert diluents has been studied and the optimum extraction conditions ascertained. The organic phase loaded with NiZ+ is passed through a column of a cationic resin (H+), which contains only the water taken up on swelling. The effect of the pH of the aqueous film surrounding the resin grains on the capacity of Vionit CS-3 (−SO3H), CM-14 (−SH) and CC-1 (−COON) has been established. The loading curves of these resins have been drawn, at the optimum pH of the aqueous film, and the resin capacities shown to increase in the order −COOH < −SH < −SO3H. The effects of the diluent and of the flow-rate on the loading of the mercaptan resins, and the optimum elution conditions with HCl solution, have also been determined. A mechanism for the ion-exchange process is proposed.

Based on an investigation of the functional and active analytical groups, a new trisazo derivative, pallatriazo, is proposed as a reagent for determining Pd(II) spectrometrically. This reagent shows high sensitivity, allowing palladium determination in the concentration range 0.05–4μg Pd(II)/ml even if platinum is present up to the ratio Pd(II)∶Pt(IV)=1∶30.

Spectrometric studies on the complexation of Zr(IV) with five new pyrazolonic derivatives were carried out. The influence of ortho-substituted groups on the operational parameters of the spectrometric method of determining Zr(IV) was investigated. The absorption spectra revealed that the wavelengths of the absorption maxima of the azopyrazolonic derivatives are different from those of the zirconium compounds. Beer-Lambert

A brief account is given of Teclu's career and his contributions as a pioneer of the study of flames.

Triaminotriphenylamine was used as a new spectrophotometric reagent for the determination of sulfur dioxyde and nitrogen dioxide in the atmosphere. The absorption maxima of SO2 and NO2 compounds differ from that of the reagent. Based on a kinetic study, the experimental conditions for the determination of sulfur dioxide in the presence of nitrogen dioxide were established.

The paper describes the conditions of polarographic reduction of trinitrotriphenylamine. The reduction occurs in 2 steps of similar height (one for trihydroxylaminotriphenyl-amine and the other for triaminotriphenylamine). The method allows the polarographic determination of trinitrotriphenylamine between 0.1–0.5 mg/ml. In the presence of silver ions, the polarographic steps are shifted to more negative potentials, which indicates formation of a compound of silver with triaminotriphenylamine.

p-Nitrosodiphenylamine as a representative of nitrosoamine group was tested as a new reagent for the spectrophotometric determination of SO2. A mixture containing: p-nitrosodiphenylamine, formaldehyde, HCl, di-methylformamide and water was added to the aqueous test solutions of sulphites forming after 5 min, a blue complex with Λmax=675 nm stable for one hour. The Lambert-Beer law was obeyed in the 0 to 50 /ug SO2/cm3 range. Molar absorptivity was equal to 2000 and the specific absorption was 0.062. The investigations should lead to search for other reagents from the nitrosoamine group suitable for this purpose.