title: Isotope dilution mass spectrometry: definitive methods and reference materials in clinical chemistry.
abstract: The application of gas chromatography-mass spectrometry (GC-MS) for the quantitative analysis of endogenous compounds as well as drugs in clinical biochemistry is taken into account. For this purpose, it is of the utmost importance the choice of a good internal standard (IS). It is demonstrated that the best IS in GC-MS is a stable isotope-labelled analogue of the analyte. In this case only we can speak of isotope dilution mass spectrometry. All the advantages and disadvantages inherent to the use of such a molecule as IS are discussed. The use of a calibration curve to perform the quantitative analysis is described, together with the criteria applied for the definition of the reliability of a method (precision, accuracy and limit of quantification). Examples taken from the literature are described.
authors.affiliation: Dipartimento di Farmacologia, Università degli Studi, Firenze.
authors.forename: M G
authors.initials: MG
authors.lastname: Giovannini
authors.forename: G
authors.initials: G
authors.lastname: Pieraccini
authors.forename: G
authors.initials: G
authors.lastname: Moneti
mesh_terms: D002624:Chemistry, Clinical / Q000295:instrumentation / Q000379:methods / Q000592:standards*; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods* / Q000592:standards; D006801:Humans; D007201:Indicator Dilution Techniques; D007554:Isotopes; D012015:Reference Standards; D013256:Steroids / Q000032:analysis
chemical_list: D007554:Isotopes; D013256:Steroids