Comparison of isotope pattern deconvolution and calibration curve quantification methods for the determination of estrone and 17β-estradiol in human serum

Publication date: Available online 9 April 2019Source: Journal of Pharmaceutical and Biomedical AnalysisAuthor(s): J. Pitarch-Motellón, N. Fabregat-Cabello, C. Le Goff, A.F. Roig-Navarro, J.V. Sancho-Llopis, E. CavalierAbstractA Liquid Chromatography coupled to tandem mass spectrometry (LC-MS/MS) based method have been developed for the determination of the main estrogen compounds –estrone (E1) and 17β-estradiol (E2)– in human serum. Two isotope dilution mass spectrometry (IDMS) quantification procedures have been used: a classical calibration curve-based method were compared to a recently developed isotope pattern deconvolution (IPD) method. IPD is based on isotopic abundance measurements and multiple linear regression. Validation was performed in terms of intra-assay repeatability (n = 5), inter-assay reproducibility (n = 9) and accuracy using spiked steroid-free serum at 5 concentration levels and 3 certified reference materials. Both methodologies meet EMEA requirements yielding recoveries between 79-106% and coefficient of variations of 1.7-8.3% along all experiments. Limits of quantification as low as 5 ng/L were achieved. 40 real samples were analysed for comparison purposes showing a great correlation between calibration and IPD concentration values. Real samples were also quantified by routine immunoassay analysis, which showed a significant proportional bias of 2.55 for E1 and good correlation for E2. While methods were considered suitable for routin...
Source: Journal of Pharmaceutical and Biomedical Analysis - Category: Drugs & Pharmacology Source Type: research