Abstract: A method of radiochemical analysis comprises the steps of providing a solid phase extraction sheet material comprising ion-specific sorptive or reactive particles and a porous matrix as carrier for the particles, and providing a fluid including an ion-containing radiochemical analyte comprising the specific ion, contacting the sheet material with the fluid for a time sufficient for the particles to selectively extract the analyte from the fluid, and analyzing the sheet material in a direct mode for quantitative or qualitative data relating to the radiochemical analyte. Solid phase extraction sheet materials and methods for their preparation are also disclosed.

Abstract: A method of radiochemical analysis having the steps of providing a solid phase extraction sheet material containing ion-specific sorptive or reactive particles in a porous matrix as carrier for the particles, and providing a fluid including an ion-containing radiochemical analyte, contacting the sheet material with the fluid for a time sufficient for the particles to selectively extract the analyte from the fluid, and analyzing the sheet material in a direct mode for quantitative or qualitative data relating to the radiochemical analyte. Solid phase extraction sheet materials and methods for their preparation are also disclosed.

Abstract: Retroreflective material including a medium containing a plurality of diffraction elements comprising light interference fringe patterns is formed by pressing a first medium having on a surface thereof a plurality of light interference fringe patterns defining an array of phase modulated fresnel zone plates onto a surface of a copy medium having a thickness equal to a given focal length associated with the fresnel zone plates and a reflective material is coated on the opposite surface of the copy medium. In making other embodiments a plurality of fringe patterns is recorded throughout the volume of a photosensitive medium.

Abstract: Retroreflective material including a medium containing a plurality of diffraction elements comprising light interference fringe patterns for enabling provision of a retroreflective effect upon light incident thereon. In making one embodiment a plurality of light interference fringe patterns defining an array of phase modulated fresnel zone plates is replicated by embossing at one surface of a copy medium having a thickness equal to a given focal length associated with the fresnel zone plates and a reflective material is coated on the opposite surface of the copy medium. In making other embodiments a plurality of fringe patterns is recorded throughout the volume of a photosensitive medium.

Abstract: Retroreflective material is made by recording an array of photoreduced images of an original geometric fresnel zone plate image in a photosensitive medium; using the developed photosensitive medium to make a stamper for embossing an array of phase modulated fresnel zone plates corresponding to the photoreduced images; using the stamper to emboss such fresnel zone plates in a transparent copy medium having a thickness equal to a given focal length associated with such fresnel zone plates to provide an array of such fresnel zone plates at one surface of the copy medium; and coating a reflective material on the opposite surface of the copy medium.