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Analysis of vitamin D and its metabolites in biological samples – Part I : Optimization and comparison of UHPSFC-MS/MS and UHPLC-MS/MS methods

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

Fat-soluble vitamin D is an essential bioactive compound important for human health. Insufficient vitamin D levels can result not only in bone disease but also in other disorders, such as cancer, metabolic disorders, and diseases related to poor immune function. The current methods commonly used for vitamin D analysis are often applied to determine the levels of the most abundant metabolite in plasma, i.e., 25-OH-D2/D3. These methods do not consider the presence of other hydroxylated and esterified metabolites, including isomers and epimers, which are typically found in low concentrations. In this study, we developed a fast and selective ultra-high performance supercritical fluid chromatography (UHPSFC) method... (More)

Fat-soluble vitamin D is an essential bioactive compound important for human health. Insufficient vitamin D levels can result not only in bone disease but also in other disorders, such as cancer, metabolic disorders, and diseases related to poor immune function. The current methods commonly used for vitamin D analysis are often applied to determine the levels of the most abundant metabolite in plasma, i.e., 25-OH-D2/D3. These methods do not consider the presence of other hydroxylated and esterified metabolites, including isomers and epimers, which are typically found in low concentrations. In this study, we developed a fast and selective ultra-high performance supercritical fluid chromatography (UHPSFC) method using a 150 mm long 1-amino anthracene (1-AA) column and a mobile phase consisting of carbon dioxide and methanol/isopropanol (1/1, v/v) mixed with 8 % water. After thorough optimization of column temperature and back pressure, the separation of four vitamin D3 esters, vitamin D3 and D2, and eight mono- and di-hydroxylated metabolites, including three groups of isomers, was achieved in 10 min. Two ion sources, atmospheric pressure chemical ionization (APCI) and atmospheric pressure photoionization optimized within this study, were compared in tandem mass spectrometry (MS/MS) detection. No significant sensitivity differences were observed. Subsequently, the same 1-AA column chemistry was examined in ultra-high performance liquid chromatography (UHPLC) as the stationary phase that could hypothetically bring different selectivity in the separation of vitamin D and its metabolites. However, this hypothesis was rejected, and C18 was used as a stationary phase in the final optimized UHPLC-MS/MS method. Despite detailed optimization, the final 15 min UHPLC method was not able to separate di-hydroxylated isomers of vitamin D3, while it enabled better resolution of esterified forms compared to UHPSFC. Optimized methods provided similar repeatability of retention times and peak areas, with RSD < 2 % and 10 %, respectively. The lowest limits of quantification were in the range of 1.2 – 4.9 ng/mL for UHPSFC-APCI-MS/MS, while for UHPLC-APCI-MS/MS, they were typically in the range of 2.6 – 9.6 ng/mL. Based on the obtained results, the UHPSFC-APCI-MS/MS method was the most promising approach for fast, selective, and sensitive analysis that could be applied in the analysis of biological samples with emphasis on the separation of both hydroxylated and esterified metabolites, including isomeric forms.

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organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Esters, Ion source, Mass spectrometry, Ultra high-performance liquid chromatography, Ultra high-performance supercritical fluid chromatography, Vitamin D
in
Journal of Chromatography B: Analytical Technologies in the Biomedical and Life Sciences
volume
1237
article number
124087
publisher
Elsevier
external identifiers
  • pmid:38513431
  • scopus:85188436484
ISSN
1570-0232
DOI
10.1016/j.jchromb.2024.124087
language
English
LU publication?
yes
id
cead4d28-88c8-4b64-9a70-7e60558fa9ab
date added to LUP
2024-04-17 15:34:32
date last changed
2024-04-22 15:21:45
@article{cead4d28-88c8-4b64-9a70-7e60558fa9ab,
  abstract     = {{<p>Fat-soluble vitamin D is an essential bioactive compound important for human health. Insufficient vitamin D levels can result not only in bone disease but also in other disorders, such as cancer, metabolic disorders, and diseases related to poor immune function. The current methods commonly used for vitamin D analysis are often applied to determine the levels of the most abundant metabolite in plasma, i.e., 25-OH-D<sub>2</sub>/D<sub>3</sub>. These methods do not consider the presence of other hydroxylated and esterified metabolites, including isomers and epimers, which are typically found in low concentrations. In this study, we developed a fast and selective ultra-high performance supercritical fluid chromatography (UHPSFC) method using a 150 mm long 1-amino anthracene (1-AA) column and a mobile phase consisting of carbon dioxide and methanol/isopropanol (1/1, v/v) mixed with 8 % water. After thorough optimization of column temperature and back pressure, the separation of four vitamin D<sub>3</sub> esters, vitamin D<sub>3</sub> and D<sub>2</sub>, and eight mono- and di-hydroxylated metabolites, including three groups of isomers, was achieved in 10 min. Two ion sources, atmospheric pressure chemical ionization (APCI) and atmospheric pressure photoionization optimized within this study, were compared in tandem mass spectrometry (MS/MS) detection. No significant sensitivity differences were observed. Subsequently, the same 1-AA column chemistry was examined in ultra-high performance liquid chromatography (UHPLC) as the stationary phase that could hypothetically bring different selectivity in the separation of vitamin D and its metabolites. However, this hypothesis was rejected, and C<sub>18</sub> was used as a stationary phase in the final optimized UHPLC-MS/MS method. Despite detailed optimization, the final 15 min UHPLC method was not able to separate di-hydroxylated isomers of vitamin D<sub>3</sub>, while it enabled better resolution of esterified forms compared to UHPSFC. Optimized methods provided similar repeatability of retention times and peak areas, with RSD &lt; 2 % and 10 %, respectively. The lowest limits of quantification were in the range of 1.2 – 4.9 ng/mL for UHPSFC-APCI-MS/MS, while for UHPLC-APCI-MS/MS, they were typically in the range of 2.6 – 9.6 ng/mL. Based on the obtained results, the UHPSFC-APCI-MS/MS method was the most promising approach for fast, selective, and sensitive analysis that could be applied in the analysis of biological samples with emphasis on the separation of both hydroxylated and esterified metabolites, including isomeric forms.</p>}},
  author       = {{Pilařová, Veronika and Socas-Rodríguez, Bárbara and Nováková, Lucie and Essén, Sofia and Holm, Cecilia and Turner, Charlotta and Sandahl, Margareta}},
  issn         = {{1570-0232}},
  keywords     = {{Esters; Ion source; Mass spectrometry; Ultra high-performance liquid chromatography; Ultra high-performance supercritical fluid chromatography; Vitamin D}},
  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 I : Optimization and comparison of UHPSFC-MS/MS and UHPLC-MS/MS methods}},
  url          = {{http://dx.doi.org/10.1016/j.jchromb.2024.124087}},
  doi          = {{10.1016/j.jchromb.2024.124087}},
  volume       = {{1237}},
  year         = {{2024}},
}