Target analyte quantification by isotope dilution LC-MS/MS directly referring to internal standard concentrations – validation for serum cortisol measurement
-
Barbara Maier
und
Michael Vogeser
Abstract
Background: Isotope dilution LC-MS/MS methods used in the clinical laboratory typically involve multi-point external calibration in each analytical series. Our aim was to test the hypothesis that determination of target analyte concentrations directly derived from the relation of the target analyte peak area to the peak area of a corresponding stable isotope labelled internal standard compound [direct isotope dilution analysis (DIDA)] may be not inferior to conventional external calibration with respect to accuracy and reproducibility.
Methods: Quality control samples and human serum pools were analysed in a comparative validation protocol for cortisol as an exemplary analyte by LC-MS/MS. Accuracy and reproducibility were compared between quantification either involving a six-point external calibration function, or a result calculation merely based on peak area ratios of unlabelled and labelled analyte.
Results: Both quantification approaches resulted in similar accuracy and reproducibility.
Conclusions: For specified analytes, reliable analyte quantification directly derived from the ratio of peak areas of labelled and unlabelled analyte without the need for a time consuming multi-point calibration series is possible. This DIDA approach is of considerable practical importance for the application of LC-MS/MS in the clinical laboratory where short turnaround times often have high priority.
This study was supported by the Hans-Fischer-Gesellschaft München.
Conflict of interest statement
Authors’ conflict of interest disclosure: The authors stated that there are no conflicts of interest regarding the publication of this article.
Research funding: None declared.
Employment or leadership: None declared.
Honorarium: None declared.
References
1. Briegel J, Sprung CL, Annane D, Singer M, Keh D, Moreno R, et al. Multicenter comparison of cortisol as measured by different methods in samples of patients with septic shock. Intensive Care Med 2009;35:2151–6.10.1007/s00134-009-1627-9Suche in Google Scholar
2. Kirchhoff F, Briegel J, Vogeser M. Quantification of free serum cortisol based on equilibrium dialysis and isotope dilution-liquid chromatography-tandem mass spectrometry. Clin Biochem 2011;44:894–9.10.1016/j.clinbiochem.2011.04.005Suche in Google Scholar PubMed
3. U.S. Department of Health and Human Services, Food and Drug Administration, Center for Drug Evaluation and Research (CDER), Center for Veterinary Medicine (CVM). Guidance for Industry – Bioanalytical Method Validation, May 2001. Available from: http://www.fda.gov/ downloads/Drugs/GuidanceComplianceRegulatory Information/Guidances/ucm070107.pdf. Accessed 28 August, 2012.Suche in Google Scholar
4. Shah VP, Midha KK, Dighe S, McGilveray IJ, Skelly JP, Yacobi A, et al. Analytical methods validation: bioavailability, bioequivalence and pharmacokinetic studies. J Pharm Sci 1992;81:309–12.10.1002/jps.2600810324Suche in Google Scholar
5. Rashed MS, Bucknall MP, Little D, Awad A, Jacob M, Alamoudi M, et al. Screening blood spots for inborn errors of metabolism by electrospray tandem mass spectrometry with a microplate batch process and a computer algorithm for automated flagging of abnormal profiles. Clin Chem 1997;43:1129–41.10.1093/clinchem/43.7.1129Suche in Google Scholar PubMed
6. Dombovári J, Becker JS, Dietze HJ. Isotope ratio measurements of magnesium and determination of magnesium concentration by reverse isotope dilution technique on small amounts of 26Mg-spiked nutrient solutions with inductively coupled plasma mass spectrometry. Int J Mass Spectrom 2000;202:231–40.10.1016/S1387-3806(00)00250-5Suche in Google Scholar
7. Stokvis E, Rosing H, Beijnen JH. Stable isotopically labeled internal standards in quantitative bioanalysis using liquid chromatography/mass spectrometry: necessity or not? Rapid Commun Mass Spectrom 2005;19:401–7.10.1002/rcm.1790Suche in Google Scholar PubMed
8. Wang S, Cyronak M, Yang E. Does a stable isotopically labeled internal standard always correct analyte response? A matrix effect study on a LC/MS/MS method for the determination of carvedilol enantiomers in human plasma. J Pharm Biomed Anal 2007;43:701–7.http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=000243802700042&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=b7bc2757938ac7a7a821505f8243d9f310.1016/j.jpba.2006.08.010Suche in Google Scholar PubMed
9. Vogeser M, Seger C. A decade of HPLC-MS/MS in the routine clinical laboratory –goals for further developments. Clin Biochem 2008;41:649–62.10.1016/j.clinbiochem.2008.02.017Suche in Google Scholar PubMed
10. Vogeser M, Kirchhoff F. Progress in automation of LC-MS in laboratory medicine. Clin Biochem 2011;44:4–13.http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=000286484600003&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=b7bc2757938ac7a7a821505f8243d9f310.1016/j.clinbiochem.2010.06.005Suche in Google Scholar PubMed
©2013 by Walter de Gruyter Berlin Boston
Artikel in diesem Heft
- Letters to the Editor
- Missing agreement between the two IMMULITE® PSA assays
- “Cerebrovascular stressing”: dipyridamole-induced S100B elevation predicts ischemic cerebrovascular events
- Discrepancy in lamellar body counts (LBCs) between the Sysmex XE-2100 and Sysmex XT-2000i instruments
- Interphase fluorescent in situ hybridization detection of the 7q11.23 chromosomal inversion in a clinical laboratory: automated versus manual scoring
- Adrenocorticotropic hormone stability in preanalytical phase depends on temperature and proteolytic enzyme inhibitor
- The impact on costs and efficiency of reducing the number of collected tubes
- Improved software on the Sysmex XE-5000 BF mode for counting leukocytes in cerebrospinal fluid
- First trimester placental growth factor and soluble fms-like tyrosine kinase 1 are significantly related to PAPP-A levels
- Preliminary evaluation of complete blood cell count on Mindray BC-6800
- Rational use of laboratory tests: albuminuria
- Masthead
- Masthead
- Editorials
- Fifty years of CCLM – invitation to join us for a reception in Milan
- Personalized (laboratory) medicine: a bridge to the future
- PSA, PCA3 and the phi losophy of prostate cancer management
- Reviews
- Gender medicine: a task for the third millennium
- Evaluation of [−2] proPSA and Prostate Health Index (phi) for the detection of prostate cancer: a systematic review and meta-analysis
- Harmonization in laboratory medicine: the complete picture
- Opinion Papers
- Glycemic control in the clinical management of diabetic patients
- Time for a conceptual shift in assessment of internal quality control for whole blood or cell-based testing systems? An evaluation using platelet function and the PFA-100 as a case example
- Guidelines and Recommendations
- A position paper of the EFLM Committee on Education and Training and Working Group on Distance Education Programmes/E-Learning: developing an e-learning platform for the education of stakeholders in laboratory medicine
- General Clinical Chemistry and Laboratory Medicine
- A novel weighted cumulative delta-check method for highly sensitive detection of specimen mix-up in the clinical laboratory
- Identification and quantification of hemoglobins in whole blood: the analytical and organizational aspects of Capillarys 2 Flex Piercing compared with agarose electrophoresis and HPLC methods
- Determination of the fatty acid profile of neutral lipids, free fatty acids and phospholipids in human plasma
- Urinary iodine concentrations of pregnant women in Ukraine
- Delay in the measurement of eosin-5′-maleimide (EMA) binding does not affect the test result for the diagnosis of hereditary spherocytosis
- Faecal calprotectin: comparative study of the Quantum Blue rapid test and an established ELISA method
- Target analyte quantification by isotope dilution LC-MS/MS directly referring to internal standard concentrations – validation for serum cortisol measurement
- Reference Values and Biological Variations
- Reference values and upper reference limits for 26 trace elements in the urine of adults living in Belgium
- Biological variation and reference change values of common clinical chemistry and haematologic laboratory analytes in the elderly population
- Indirect determination of pediatric blood count reference intervals
- Cancer Diagnostics
- Suitability of quality control materials for prostate-specific antigen (PSA) measurement: inter-method variability of common tumor marker control materials
- Prostate cancer antigen 3 (PCA3) RNA detection in blood and tissue samples for prostate cancer diagnosis
- Serum levels of cancer biomarkers in diabetic and non-diabetic proteinuric patients: a preliminary study
- Infectious Diseases
- Polymorphic mononuclear neutrophils CD64 index for diagnosis of sepsis in postoperative surgical patients and critically ill patients
- Plasma long pentraxin 3 (PTX3) concentration is a novel marker of disease activity in patients with community-acquired pneumonia
Artikel in diesem Heft
- Letters to the Editor
- Missing agreement between the two IMMULITE® PSA assays
- “Cerebrovascular stressing”: dipyridamole-induced S100B elevation predicts ischemic cerebrovascular events
- Discrepancy in lamellar body counts (LBCs) between the Sysmex XE-2100 and Sysmex XT-2000i instruments
- Interphase fluorescent in situ hybridization detection of the 7q11.23 chromosomal inversion in a clinical laboratory: automated versus manual scoring
- Adrenocorticotropic hormone stability in preanalytical phase depends on temperature and proteolytic enzyme inhibitor
- The impact on costs and efficiency of reducing the number of collected tubes
- Improved software on the Sysmex XE-5000 BF mode for counting leukocytes in cerebrospinal fluid
- First trimester placental growth factor and soluble fms-like tyrosine kinase 1 are significantly related to PAPP-A levels
- Preliminary evaluation of complete blood cell count on Mindray BC-6800
- Rational use of laboratory tests: albuminuria
- Masthead
- Masthead
- Editorials
- Fifty years of CCLM – invitation to join us for a reception in Milan
- Personalized (laboratory) medicine: a bridge to the future
- PSA, PCA3 and the phi losophy of prostate cancer management
- Reviews
- Gender medicine: a task for the third millennium
- Evaluation of [−2] proPSA and Prostate Health Index (phi) for the detection of prostate cancer: a systematic review and meta-analysis
- Harmonization in laboratory medicine: the complete picture
- Opinion Papers
- Glycemic control in the clinical management of diabetic patients
- Time for a conceptual shift in assessment of internal quality control for whole blood or cell-based testing systems? An evaluation using platelet function and the PFA-100 as a case example
- Guidelines and Recommendations
- A position paper of the EFLM Committee on Education and Training and Working Group on Distance Education Programmes/E-Learning: developing an e-learning platform for the education of stakeholders in laboratory medicine
- General Clinical Chemistry and Laboratory Medicine
- A novel weighted cumulative delta-check method for highly sensitive detection of specimen mix-up in the clinical laboratory
- Identification and quantification of hemoglobins in whole blood: the analytical and organizational aspects of Capillarys 2 Flex Piercing compared with agarose electrophoresis and HPLC methods
- Determination of the fatty acid profile of neutral lipids, free fatty acids and phospholipids in human plasma
- Urinary iodine concentrations of pregnant women in Ukraine
- Delay in the measurement of eosin-5′-maleimide (EMA) binding does not affect the test result for the diagnosis of hereditary spherocytosis
- Faecal calprotectin: comparative study of the Quantum Blue rapid test and an established ELISA method
- Target analyte quantification by isotope dilution LC-MS/MS directly referring to internal standard concentrations – validation for serum cortisol measurement
- Reference Values and Biological Variations
- Reference values and upper reference limits for 26 trace elements in the urine of adults living in Belgium
- Biological variation and reference change values of common clinical chemistry and haematologic laboratory analytes in the elderly population
- Indirect determination of pediatric blood count reference intervals
- Cancer Diagnostics
- Suitability of quality control materials for prostate-specific antigen (PSA) measurement: inter-method variability of common tumor marker control materials
- Prostate cancer antigen 3 (PCA3) RNA detection in blood and tissue samples for prostate cancer diagnosis
- Serum levels of cancer biomarkers in diabetic and non-diabetic proteinuric patients: a preliminary study
- Infectious Diseases
- Polymorphic mononuclear neutrophils CD64 index for diagnosis of sepsis in postoperative surgical patients and critically ill patients
- Plasma long pentraxin 3 (PTX3) concentration is a novel marker of disease activity in patients with community-acquired pneumonia
