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Analysis of vitamin D and its metabolites in biological samples – Part II : Optimization of a sample preparation method for liver tissue

Pilařová, Veronika LU ; Socas-Rodríguez, Bárbara ; Nováková, Lucie ; Holm, Cecilia LU ; Sandahl, Margareta LU and Turner, Charlotta LU (2024) In Journal of Chromatography B: Analytical Technologies in the Biomedical and Life Sciences 1237.
Abstract

Extraction of vitamin D, including its hydroxylated and esterified metabolites, from soft tissues such as the liver is challenging due to the lipophilic character of matrix and analytes that are expected in very low concentration levels. In this study, we aimed at the optimization of two-step extraction using solid–liquid extraction as the first step, followed by solid-phase extraction. Various solvents, including ethanol, acetonitrile, methanol, acetone, heptane, and heptane with isopropanol, were investigated to isolate vitamin D compounds from liver tissue in the first step. Acetone was finally selected as the most suitable solvent for the solid–liquid extraction, with the highest recovery in the range of 67 – 98% for polar... (More)

Extraction of vitamin D, including its hydroxylated and esterified metabolites, from soft tissues such as the liver is challenging due to the lipophilic character of matrix and analytes that are expected in very low concentration levels. In this study, we aimed at the optimization of two-step extraction using solid–liquid extraction as the first step, followed by solid-phase extraction. Various solvents, including ethanol, acetonitrile, methanol, acetone, heptane, and heptane with isopropanol, were investigated to isolate vitamin D compounds from liver tissue in the first step. Acetone was finally selected as the most suitable solvent for the solid–liquid extraction, with the highest recovery in the range of 67 – 98% for polar hydroxylated forms and 3 – 28% for lipophilic vitamin D and esters. Two solid phase extraction (SPE) based on the (i) “bind and elute strategy” and (ii) “removal strategy” using hydrophilic-lipophilic balanced SPE sorbent were optimized as a proceeding step for acetone extracts to increase the method selectivity. Finally, two optimized methods, combining solid–liquid extraction and individual SPE strategy, were examined in terms of sensitivity, recovery, matrix effect, accuracy, and precision. The limits of quantification were in the range of 1 – 10 ng/mL and 3 – 20 ng/mL analyzed by ultra-high performance supercritical fluid chromatography and ultra-high performance liquid chromatography hyphenated a with tandem mass spectrometer, respectively. The absolute recovery determined for the “bind and elute strategy” protocol was in the range of 3 – 24 %. Nevertheless, this method was free of matrix effects, which were determined to be in the 73 – 120 % range. On the contrary, the “removal strategy” approach provided higher recovery values for all compounds (47 – 123 %), but the results for nonpolar vitamin D and esters were strongly affected by signal suppression (matrix effects 3 – 51 %). Both methods fulfilled the criteria for accuracy and precision requested by the European Medicine Agency Guideline on Bioanalysis. “Removal strategy” SPE with decreased manual intervention and lower solvent consumption was finally applied to mouse liver tissue to determine vitamin D and its hydroxylated and esterified metabolites for the first time. The results, i.e., vitamin D esters detected in liver tissue, supported the notion that esters of vitamin D can be stored in lipophilic tissues to release vitamin D.

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organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Acetone, Mass spectrometry, Solid phase extraction, Solid–liquid extraction, Ultra-high performance supercritical fluid chromatography, vitamin D esters
in
Journal of Chromatography B: Analytical Technologies in the Biomedical and Life Sciences
volume
1237
article number
124088
publisher
Elsevier
external identifiers
  • pmid:38520897
  • scopus:85188655388
ISSN
1570-0232
DOI
10.1016/j.jchromb.2024.124088
language
English
LU publication?
yes
id
7abefa23-758d-4299-bb35-2feb0bf76d5a
date added to LUP
2024-04-17 15:10:52
date last changed
2024-04-22 15:22:02
@article{7abefa23-758d-4299-bb35-2feb0bf76d5a,
  abstract     = {{<p>Extraction of vitamin D, including its hydroxylated and esterified metabolites, from soft tissues such as the liver is challenging due to the lipophilic character of matrix and analytes that are expected in very low concentration levels. In this study, we aimed at the optimization of two-step extraction using solid–liquid extraction as the first step, followed by solid-phase extraction. Various solvents, including ethanol, acetonitrile, methanol, acetone, heptane, and heptane with isopropanol, were investigated to isolate vitamin D compounds from liver tissue in the first step. Acetone was finally selected as the most suitable solvent for the solid–liquid extraction, with the highest recovery in the range of 67 – 98% for polar hydroxylated forms and 3 – 28% for lipophilic vitamin D and esters. Two solid phase extraction (SPE) based on the (i) “bind and elute strategy” and (ii) “removal strategy” using hydrophilic-lipophilic balanced SPE sorbent were optimized as a proceeding step for acetone extracts to increase the method selectivity. Finally, two optimized methods, combining solid–liquid extraction and individual SPE strategy, were examined in terms of sensitivity, recovery, matrix effect, accuracy, and precision. The limits of quantification were in the range of 1 – 10 ng/mL and 3 – 20 ng/mL analyzed by ultra-high performance supercritical fluid chromatography and ultra-high performance liquid chromatography hyphenated a with tandem mass spectrometer, respectively. The absolute recovery determined for the “bind and elute strategy” protocol was in the range of 3 – 24 %. Nevertheless, this method was free of matrix effects, which were determined to be in the 73 – 120 % range. On the contrary, the “removal strategy” approach provided higher recovery values for all compounds (47 – 123 %), but the results for nonpolar vitamin D and esters were strongly affected by signal suppression (matrix effects 3 – 51 %). Both methods fulfilled the criteria for accuracy and precision requested by the European Medicine Agency Guideline on Bioanalysis. “Removal strategy” SPE with decreased manual intervention and lower solvent consumption was finally applied to mouse liver tissue to determine vitamin D and its hydroxylated and esterified metabolites for the first time. The results, i.e., vitamin D esters detected in liver tissue, supported the notion that esters of vitamin D can be stored in lipophilic tissues to release vitamin D.</p>}},
  author       = {{Pilařová, Veronika and Socas-Rodríguez, Bárbara and Nováková, Lucie and Holm, Cecilia and Sandahl, Margareta and Turner, Charlotta}},
  issn         = {{1570-0232}},
  keywords     = {{Acetone; Mass spectrometry; Solid phase extraction; Solid–liquid extraction; Ultra-high performance supercritical fluid chromatography; vitamin D esters}},
  language     = {{eng}},
  month        = {{04}},
  publisher    = {{Elsevier}},
  series       = {{Journal of Chromatography B: Analytical Technologies in the Biomedical and Life Sciences}},
  title        = {{Analysis of vitamin D and its metabolites in biological samples – Part II : Optimization of a sample preparation method for liver tissue}},
  url          = {{http://dx.doi.org/10.1016/j.jchromb.2024.124088}},
  doi          = {{10.1016/j.jchromb.2024.124088}},
  volume       = {{1237}},
  year         = {{2024}},
}