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The purpose of the study was to identify the infl uence of reactive mixture concentration (23-48 g/100 mL), pH (6.5-9.0), presence of NaCl (0.05-0.25 mol/L) and enzyme dose (2850-28,500 LAU/100 g of lactose) on the synthesis of galactosyl mannitol derivative using β-galactosidase from Kluyveromyces lactis. The use of the enzyme dose ranging from 2850 to 11,400 LAU/100 g lactose allowed obtaining gal-mannitol at the level of 21.8% total saccharides; higher doses intensifi ed product decomposition. An increase in the concentration of the reactive mixture had a positive impact on the quantity of gal-mannitol obtained every single time, i.e. 4.39 g were obtained from 100 mL of a 23 g/100 mL solution and over 10 g were obtained from a 48 g/100 mL solution. A relatively low increase in product quantity (by ca. 5%) occurred after the pH was increased from 6.5 to 9.0. The use of NaCl rendered better results. An increase in the maximum content of gal-mannitol in the total sugar by 12.8% was observed at the concentration of 0.25 mol/L.

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In this study, the extraction of nickel(II) ions from sulphate and sulphate/chloride solutions with 2-, 3-, and 4-pyridylketoximes was investigated. The effect of different variables influencing the extraction of nickel(II) ions such as the extractant structure and the concentration of hydrogen ion, sulphate, and chloride ions have been studied. The shaking time and temperature also influenced metal ion removal. It was found that the hydrophobic 2-pyridylketoximes are the most effective extractants for nickel ions from sulphate/chloride solutions. The discussion also includes the mechanism of nickel(II) complexation by the hydrophobic pyridylketoximes and the speciation of nickel(II) in the presence of chloride and sulphate ions.