Multilayer analytical element

A multilayer analytical element for the analysis of a substance in a liquid sample comprising a liquid sample-spreading layer, a reagent layer containing a diazonium salt and a liquid-impermeable light-transmissive support, in which said reagent layer contains a polymer containing at least 10 molar % of a repeating unit selected from those consisting of a repeating unit having a sulfoalkyl group and a repeating unit having a sulfophenyl group, and in which a nondiffusive base-containing layer is provided under the condition that the nondiffusive base-containing layer is in liquid contact with said reagent layer, and wherein said polymer provides a pH environment which preserves the diazonium salt in the reagent layer.

A multilayer analytical element for analysis of a substance in a liquid sample comprising a porous reagent layer containing a diazonium salt and a liquid impermeable light-transmissive support, in which said porous reagent layer contains a polymer containing at least 30 molar % of a repeating unit having a sulfophenyl group, and wherein said polymer provides a pH environment which preserves the diazonium salt in the reagent layer.

A multilayer analytical element for analysis of a substance in a liquid sample comprising a porous reagent layer containing a diazonium salt and a liquid impermeable light-transmissive support, in which which said porous reagent layer contains a polymer containng at leasts 30 molar % of a repeating unit selected from those consisting of a repeating unit having a sulfoalkyl group and a repeating unit having a sulfophenyl group, and in which a nondiffusive base containing layer is provided under the condition that the nondiffusive base-containing layer is in liquid contact with said porous reagent layer, and wherein said polymer provides a pH environment which preserves the diazonium salt in the reagent layer.