Abstract: The present invention relates to a packaging material for reduced transfer from a package to its content of substances causing undesirable taste and/or hazardous substances, this reduction being due to the packaging material containing a hydrophobic zeolite. More specifically, the invention concerns paperboard, in which case the substances causing undesirable taste mainly are naturally occurring extractive substances, oxidation products thereof and, to a lesser extent, the paper chemicals present. Further, the presence of a hydrophobic zeolite in the paperboard enhances the water-repellent (hydrophobic) capacity. Also, the present invention concerns a method for production of a packaging material of paper, board or paperboard by forming and dewatering a suspension of lignocellulose-containing fibres, where the dewatering takes place in the presence of a hydrophobic zeolite.

Abstract: The invention relates to a method of determining the content of hydrogen peroxide in an aqueous solution, which is brought to a pH below 3, supplied with an excess of I.sup.-, and irradiated with light, the absorbance being measured at a predetermined wavelength. The invention also relates to an analyser for carrying out the method. Further, the invention relates to a method and a system of controlling the supply of hydrogen peroxide to an aqueous solution.