title: Precise spectrophotometry of small quantities of drugs in the presence of irreproducible quantities of impurities.
abstract: A variety of methods of spectrophotometric assay of compounds in the presence of one or more irrelevant impurities have been recently described, employing, for example, the use of Legendre polynomials and trigonometric functions. The use of least-squares solutions of overdetermined systems (Scheid 1968) in spectrophotometry is outlined, with conditions under which simplified overdetermined systems have been used for precise spectrophotometric assay of small quantities of drug substances in the presence of largely irreproducible quantities of irrelevant impurities.
mesh_terms: D002626:Chemistry, Pharmaceutical; D004340:Drug Contamination; D008722:Methods; D004364:Pharmaceutical Preparations / Q000032:analysis*; D013053:Spectrophotometry
chemical_list: D004364:Pharmaceutical Preparations