| 摘要 |
PURPOSE:To obtain a monolithic multilayered analyzing material having high sensitivity and high accuracy by providing a liquid shielding layer consisting of a porous material which permits the transmission of gaseous ammonia but does not permit the transmission liquid between an indicator layer and a reagent layer in lieu of conventional permselective layers. CONSTITUTION:An indicator layer contg. such a compd. which produces a change in absorption wavelength by reacting with gaseous ammonia such as, for example, a leucocyanine dye is provided on hydrophobic transparent backing of, for example, polyethylene terephthalate or the like. A membrane filter made of cellulose acetate or the like is formed of a porous material of 50-300mum thickness and >=25% voids, whereby a liquid shielding layer is provided on said indicator layer. In the case of a hydrophilic material, the layer is subjected to a water repelling treatment with silicone oil or the like. A reagent such as urease which forms ammonia by reacting with ammonia forming substrates is provided on said layer. Thus the diffusion speed of gaseous ammonia is increased by the presence of the air layers and the time for measurement is markedly reduced. |
