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

Autores de IIS La Fe

• Neus Fabregat Cabello

  Autor

Participantes ajenos a IIS La Fe

• Pitarch-Motellon, J
• Le Goff, C
• Roig-Navarro, AF
• Sancho-Llopis, JV
• Cavalier, E

Grupos

• Hematología y Hemoterapia

  

  Investigador Principal

  Javier De La Rubia Comos

Abstract

A Liquid Chromatography coupled to tandem mass spectrometry (LC-MS/MS) based method have been developed for the determination of the main estrogen compounds -estrone (El) and 17 beta-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 routine or countercheck analysis within the context of hospital's needs, IPD has demonstrated to be faster and cost saving. (C) 2019 Elsevier B.V. All rights reserved.

Keywords

• Estrone; 17 beta-estradiol; Serum; LC-MS/MS; Isotope dilution mass spectrometry; Isotope pattern deconvolution