Abstract: Test device and method for the semi-quantitative determination of chlorine dioxide in a liquid sample has at least two carrier matrices. The first carrier matrix comprises at least one amino acid, sodium thiosulphate, at least one redox indicator, buffer substances and at least one surfactant. The second carrier matrix comprises at least one inorganic iodide salt, starch and/or at least one starch derivative, sodium thiosulfate, buffer substances and at least one surfactant.

Abstract: A method for treating a plurality of indicator fields for determining the pH-value of an aqueous solution is provided. Each of the indicator fields contains at least one indicator dye, which is fixed in a non-bleeding manner, in particular on a layer including cellulose or regenerated cellulose, and changes its color within a pH-turning-range. The indicator fields having buffer capacities which differ from one another. All the indicator fields are impregnated from the outside with an impregnation which influences the buffer capacities of the indicator fields in such a way that the deviations are levelled.

Abstract: The present invention relates to a device for determining the concentration of inorganic phosphate, especially orthophosphate, where said device is a test matrix including a molybdate salt, a solid acid, a PVP derivative, and a mixture of at least two different chromogenic reducing agents. In addition, the invention relates to a process for increasing the sensitivity of a test device.

Abstract: Test device and method for the semi-quantitative determination of chlorine dioxide in a liquid sample has at least two carrier matrices. The first carrier matrix comprises at least one amino acid, sodium thiosulphate, at least one redox indicator, buffer substances and at least one surfactant. The second carrier matrix comprises at least one inorganic iodide salt, starch and/or at least one starch derivative, sodium thiosulfate, buffer substances and at least one surfactant.

Abstract: A method for treating a plurality of indicator field for determining the pH-value of an aqueous solution is disclosed. The indicator fields each contain at least one indicator dye, which is fixed in a non-bleeding manner, in particular on a layer comprising cellulose or regenerated cellulose, and changes its color within a pH-turning-range. The indicator fields having buffer capacities which differ from one another. All the indicator fields are impregnated from the outside with an impregnation which influences the buffer capacities of the indicator fields in such a way that the deviations are leveled.

Abstract: The present disclosure relates to a test device for the pH-dependent detection of urine by the combined immobilization on the cellulose-containing support matrix of the pH indicator dye and the acid/base reacted with it. In addition, the present disclosure relates to a sanitary article comprising the test device according to the present disclosure, and a process for preparing the test device according to the present disclosure.

Abstract: The present invention relates to a device for determining the concentration of inorganic phosphate, especially orthophosphate, where said device is a test matrix including a molybdate salt, a solid acid, a PVP derivative, and a mixture of at least two different chromogenic reducing agents. In addition, the invention relates to a process for increasing the sensitivity of a test device.