Patent ID: 6362891
Filing Date: 2002-03-26
Classification: G01N

Abstract:
A method of analysing powder formed as a mixture of ingredients and derived from a bulk preparation thereof which comprises predetermining an assay standard spectrum for a relevant ingredient of the bulk powder mixture by spectrophotometrically analysing characteristics of that relevant ingredient from transmission measurements of a beam of electromagnetic radiation applied to and passing through the relevant ingredient to provide a spectrum of absorption characteristics at known wavelengths of the beam;removing a sample of powder from the bulk mixture and pressing powder of the sample into a self-supporting test wafer; spectrophotometrically analysing characteristics of the material of the test wafer from transmission measurements of the beam of electromagnetic radiation applied to and passing through the wafer to provide an assay test spectrum of actual absorption characteristics of ingredients in the material of the test wafer for known wavelengths of the beam, and comparing absorption characteristics from said assay standard spectrum with said assay test spectrum at predetermined wavelengths of the beam to assess acceptability of the relevant ingredient in the powder of the sample.