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Uncovering the origin of impurities in supercritical fluid chromatography coupled to high-resolution mass spectrometry

Bajramova, Azemina LU ; Synefakis, Evangelos ; Larsen, Jesper LU ; Hjorth, Jeppe Lindegaard LU ; Turner, Charlotta LU orcid and Sandahl, Margareta LU orcid (2026) In Journal of Chromatography A 1778.
Abstract

Maintaining low background levels is essential for analytical instruments, such as in supercritical fluid chromatography (SFC) coupled to high-resolution mass spectrometry (HRMS). An approximate tenfold increase of the background was observed in our laboratory when a new CO2 cylinder with a dip tube was installed on a SFCHRMS system. Most analyte peaks were obscured. This study aimed to find the cause of the elevated background. Accordingly, the entire system was cleaned and each module, including the ion source, back pressure regulator, column, autosampler, solvent pumps, CO2 pump, and cylinder, were assessed. The troubleshooting suggested that the source of the contamination was the CO2 cylinder. A... (More)

Maintaining low background levels is essential for analytical instruments, such as in supercritical fluid chromatography (SFC) coupled to high-resolution mass spectrometry (HRMS). An approximate tenfold increase of the background was observed in our laboratory when a new CO2 cylinder with a dip tube was installed on a SFCHRMS system. Most analyte peaks were obscured. This study aimed to find the cause of the elevated background. Accordingly, the entire system was cleaned and each module, including the ion source, back pressure regulator, column, autosampler, solvent pumps, CO2 pump, and cylinder, were assessed. The troubleshooting suggested that the source of the contamination was the CO2 cylinder. A statistically significant (p < 0.05) elevation in the background was observed when liquid CO2 was used as mobile phase. The ions present above normal background levels were found to have m/z of 492.3439, 495.2934, 371.2434, and 490.3381. Annotation of the most abundant ion (m/z of 490.3381) based on m/z, isotope pattern, fragmentation pattern, and collision cross section, suggested structures resembling derivatives of sphingo- and glycolipids. A possible source could be degradation products formed during bioethanol production, the process from which the CO2 in the cylinder originates. Noteworthily, another SFCHRMS system that uses condensed gaseous CO2 instead of liquid CO2, has so far not resulted in any contamination-related issues. To prevent contamination in sensitive SFC-HRMS systems, it is essential to assess the purity of the CO₂ before use, especially if liquid CO2 from a cylinder with dip tube is used.

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author
; ; ; ; and
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Contamination, High-resolution mass spectrometry, Supercritical fluid chromatography, Troubleshooting
in
Journal of Chromatography A
volume
1778
article number
466995
publisher
Elsevier
external identifiers
  • scopus:105036240054
  • pmid:42001667
ISSN
0021-9673
DOI
10.1016/j.chroma.2026.466995
language
English
LU publication?
yes
id
8cf6823e-d99c-427c-988a-523b2cfb5357
date added to LUP
2026-05-20 14:26:13
date last changed
2026-09-14 09:54:47
@article{8cf6823e-d99c-427c-988a-523b2cfb5357,
  abstract     = {{<p>Maintaining low background levels is essential for analytical instruments, such as in supercritical fluid chromatography (SFC) coupled to high-resolution mass spectrometry (HRMS). An approximate tenfold increase of the background was observed in our laboratory when a new CO<sub>2</sub> cylinder with a dip tube was installed on a SFCHRMS system. Most analyte peaks were obscured. This study aimed to find the cause of the elevated background. Accordingly, the entire system was cleaned and each module, including the ion source, back pressure regulator, column, autosampler, solvent pumps, CO<sub>2</sub> pump, and cylinder, were assessed. The troubleshooting suggested that the source of the contamination was the CO<sub>2</sub> cylinder. A statistically significant (p &lt; 0.05) elevation in the background was observed when liquid CO<sub>2</sub> was used as mobile phase. The ions present above normal background levels were found to have m/z of 492.3439, 495.2934, 371.2434, and 490.3381. Annotation of the most abundant ion (m/z of 490.3381) based on m/z, isotope pattern, fragmentation pattern, and collision cross section, suggested structures resembling derivatives of sphingo- and glycolipids. A possible source could be degradation products formed during bioethanol production, the process from which the CO<sub>2</sub> in the cylinder originates. Noteworthily, another SFCHRMS system that uses condensed gaseous CO<sub>2</sub> instead of liquid CO<sub>2</sub>, has so far not resulted in any contamination-related issues. To prevent contamination in sensitive SFC-HRMS systems, it is essential to assess the purity of the CO₂ before use, especially if liquid CO<sub>2</sub> from a cylinder with dip tube is used.</p>}},
  author       = {{Bajramova, Azemina and Synefakis, Evangelos and Larsen, Jesper and Hjorth, Jeppe Lindegaard and Turner, Charlotta and Sandahl, Margareta}},
  issn         = {{0021-9673}},
  keywords     = {{Contamination; High-resolution mass spectrometry; Supercritical fluid chromatography; Troubleshooting}},
  language     = {{eng}},
  publisher    = {{Elsevier}},
  series       = {{Journal of Chromatography A}},
  title        = {{Uncovering the origin of impurities in supercritical fluid chromatography coupled to high-resolution mass spectrometry}},
  url          = {{http://dx.doi.org/10.1016/j.chroma.2026.466995}},
  doi          = {{10.1016/j.chroma.2026.466995}},
  volume       = {{1778}},
  year         = {{2026}},
}