{"term":{"id":"08022","title":"limit of quantification","longtitle":"IUPAC Gold Book - limit of quantification","doi":"10.1351\/goldbook.08022","code":"08022","status":"current","initialism":"<em>initialism<\/em>: LOQ","synonym":"<em>synonym<\/em>: quantification limit","definitions":[{"id":1,"text":"Smallest or largest measured quantity value, obtained by a given measurement procedure, which fulfils a requirement of fitness for purpose.","notes":{"1":"The quantity measured is usually a mass fraction or a concentration but can also be for example, a mass or an amount of substance.","2":"The requirement can, for example, be a standard deviation under repeatability conditions of measurement or a measurement uncertainty.","3":"The smallest and largest measured quantity values correspond to the lower limit of quantification (LLOQ) and the upper limit of quantification (ULOQ), respectively. The interval between the LLOQ and ULOQ is the working interval.","4":"If the LLOQ is estimated as a multiple of the standard deviation of measured values of a blank material (or one spiked with a small aliquot of the component) obtained under repeatability conditions of measurement, it is important to document the multiplication factor, which may be 5, 6, or 10, applied so that different values stated for the LLOQ can be compared."},"links":[{"term":"blank material","url":"https:\/\/goldbook.iupac.org\/\/terms\/view\/08010"},{"term":"fitness for purpose","url":"https:\/\/goldbook.iupac.org\/\/terms\/view\/08073"},{"term":"measurement procedure","url":"https:\/\/goldbook.iupac.org\/\/terms\/view\/08028"},{"term":"repeatability conditions of measurement","url":"https:\/\/goldbook.iupac.org\/\/terms\/view\/08040"},{"term":"requirement","url":"https:\/\/goldbook.iupac.org\/\/terms\/view\/08122"},{"term":"working interval","url":"https:\/\/goldbook.iupac.org\/\/terms\/view\/08051"}],"sources":["PAC, 2021, 93, 997. 'Metrological and quality concepts in analytical chemistry (IUPAC Recommendations 2021)' on page 1007 (https:\/\/doi.org\/10.1515\/pac-2019-0819)"]}],"altoutputs":{"html":"https:\/\/goldbook.iupac.org\/terms\/view\/08022\/html","xml":"https:\/\/goldbook.iupac.org\/terms\/view\/08022\/xml","plain":"https:\/\/goldbook.iupac.org\/terms\/view\/08022\/plain"},"citation":"Citation: 'limit of quantification' in IUPAC Compendium of Chemical Terminology, 5th ed. International Union of Pure and Applied Chemistry; 2025. Online version 5.0.0, 2025. 10.1351\/goldbook.08022","license":"The IUPAC Gold Book is licensed under Creative Commons Attribution-ShareAlike CC BY-SA 4.0 International (https:\/\/creativecommons.org\/licenses\/by-sa\/4.0\/) for individual terms.","collection":"If you are interested in licensing the Gold Book for commercial use, please contact the IUPAC Executive Director at executivedirector@iupac.org .","disclaimer":"The International Union of Pure and Applied Chemistry (IUPAC) is continuously reviewing and, where needed, updating terms in the Compendium of Chemical Terminology (the IUPAC Gold Book). Users of these terms are encouraged to include the version of a term with its use and to check regularly for updates to term definitions that you are using.","accessed":"2026-04-18T20:56:57+00:00"}}