A method for the trace analysis of rhodamine and eosine with colorimetric measurements based on solid-phase extraction (SPE) by transparent polymethacrylate matrix (PMM) is described. Solid-phase extraction on PMM allowed a 380-fold enrichment of the dyes if 10 mL sample volume is used with extraction efficiencies 98%. The method enables the determination of rhodamine to 0.06 mg/L and eosine to 1.2 mg/L combined with a fast and easy sample-preparation (pH-adjusting prior to SPE). Simultaneous extraction and determination of rhodamine and eosine in reservoir samples with high salinity confirmed the applicability and reproducibility of the method. Batch adsorption results indicated that Langmuir isotherm described the adsorption isotherms better.

The article shows the efficient use of natural apatite ore in purification of mining industrial wastewaters from heavy metal ions. The determination of adsorption constants, calculation of...

The results of the catalytic hydrogenation of a three-component anthracene-benzothiophene-biphenyl mixture in the presence of different catalytic additives are given. It was found that the conversion of the mixture of model substances was 85.9 or 85.0% with the use of FeS₂ or Fe₂O₃ + S (1 : 1), respectively; in both cases, hydrocracking was the prevailing reaction path. A comparatively small difference was found in the products of hydrogenation and hydroisomerization, which was related to the hydrogenation of the structure of each particular component.

Temperature dependences of the heat capacities of cobalt manganites LaM2IICoMnO6 (MII= Mg, Ca, Sr, Ba) are investigated by means of dynamic calorimetry in the temperature range of 298.15–673 K. It...