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  2. Chemical purity - Wikipedia

    en.wikipedia.org/wiki/Chemical_purity

    In chemistry, chemical purity is the measurement of the amount of impurities found in a sample. Several grades of purity are used by the scientific, pharmaceutical, and industrial communities. Several grades of purity are used by the scientific, pharmaceutical, and industrial communities.

  3. Assay - Wikipedia

    en.wikipedia.org/wiki/Assay

    An assay (analysis) is never an isolated process, as it must be accompanied with pre- and post-analytic procedures. Both the communication order (the request to perform an assay plus related information) and the handling of the specimen itself (the collecting, documenting, transporting, and processing done before beginning the assay) are pre-analytic steps.

  4. Assay office - Wikipedia

    en.wikipedia.org/wiki/Assay_office

    Assay offices are institutions set up to assay (test the purity of) precious metals. This is often done to protect consumers from buying fake items. Upon successful completion of an assay (i.e. if the metallurgical content is found be equal or better than that claimed by the maker and it otherwise conforms to the prevailing law) the assay offices typically stamp a hallmark on the item to ...

  5. Metallurgical assay - Wikipedia

    en.wikipedia.org/wiki/Metallurgical_assay

    The precious metal purity and content of these coins is guaranteed by the respective mint or government, and, therefore, the assay of the raw materials and finished coins is an important quality control. In the UK, the Trial of the Pyx is a ceremonial procedure for ensuring that newly minted coins conform to required standards.

  6. Certified reference materials - Wikipedia

    en.wikipedia.org/wiki/Certified_reference_materials

    Pure substances; essentially pure chemicals, characterised for chemical purity and/or trace impurities. Standard solutions and gas mixtures, often prepared gravimetrically from pure substances. Matrix reference materials, characterised for the composition of specified major, minor or trace chemical constituents.

  7. Purity - Wikipedia

    en.wikipedia.org/wiki/Purity

    Purity, the proportion of a named pure substance in a sample (by weight, mass, volume, or count) Fineness, several units of purity of precious metals; Nine (purity), an informal unit of purity; Purity, the colorfulness of a light source; Purity (quantum mechanics), a measure of correlation between a system and its environment

  8. Isotope dilution - Wikipedia

    en.wikipedia.org/wiki/Isotope_dilution

    Both of these variables are hard to establish since isotopically enriched substances are generally available in small quantities of questionable purity. As a result, before isotope dilution is performed on the sample, the amount of the enriched analyte is ascertained beforehand using isotope dilution.

  9. Metal testing - Wikipedia

    en.wikipedia.org/wiki/Metal_Testing

    Metal testing is a process or procedure used to check composition of an unknown metallic substance. [1] There are destructive processes and nondestructive processes. Metal testing can also include, determining the properties of newly forged metal alloys.