Internal & external audits: first-, second-, and third-party audits. 1  A first-party audit is performed within an organization to measure its strengths and weaknesses against its own procedures or methods and/or against external standards adopted by (voluntary) or imposed on (mandatory) the organization.
Precursor (chemistry) In chemistry, a precursor is a compound that participates in a chemical reaction that produces another compound. In biochemistry, the term precursor often refers more specifically to a chemical compound preceding another in a metabolic pathway, such as a protein precursor. 1 Illicit drug precursors.
Morphine is a precursor in the manufacture in a large number of opioids such as dihydromorphine, hydromorphone, nicomorphine, and heroin as well as codeine, which itself has a large family of semi-synthetic derivatives.