Quantification of Trimethylamine-<i>N</i>-Oxide and Trimethylamine in Fish Oils for Human Consumption

Supplementing fish oil is one of the strategies to reduce the risk of cardiovascular disease, the leading cause of death around the world. Contradictorily, fish oil may also contain trimethylamine-<i>N</i>-oxide, a recently emerged risk factor for cardiovascular disease, as well as one o...

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Main Authors: Dominik Dörfel, Sascha Rohn, Eckard Jantzen
Format: Article
Language:English
Published: MDPI AG 2024-03-01
Series:Molecules
Subjects:
Online Access:https://www.mdpi.com/1420-3049/29/6/1339
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author Dominik Dörfel
Sascha Rohn
Eckard Jantzen
author_facet Dominik Dörfel
Sascha Rohn
Eckard Jantzen
author_sort Dominik Dörfel
collection DOAJ
description Supplementing fish oil is one of the strategies to reduce the risk of cardiovascular disease, the leading cause of death around the world. Contradictorily, fish oil may also contain trimethylamine-<i>N</i>-oxide, a recently emerged risk factor for cardiovascular disease, as well as one of its precursors, trimethylamine. A method suitable for routine quantification of trimethylamine-<i>N</i>-oxide and trimethylamine in fish oil with a quick and easy liquid extraction without derivatization has been developed. Liquid chromatography with tandem mass spectrometry detection was employed along with a zwitterionic hydrophilic interaction liquid chromatography column and a gradient elution with eluents containing 50 mmol/L of ammonium formate. An internal standard (triethylamine) was used for quantification by mass spectrometry with an external calibration. The assay proved high linearity in the ranges of 10 to 100 ng/mL and 100 to 1000 ng/mL for trimethylamine-<i>N</i>-oxide and trimethylamine, respectively. The lowest limit of quantification was determined to be 100 µg/kg for trimethylamine and 10 µg/kg for trimethylamine-<i>N</i>-oxide, with the limit of detection at 5 µg/kg and 0.25 µg/kg, respectively. Accuracy ranged from 106–119%. Precision was below 7% the relative standard deviation for both analytes. The method was successfully applied for the determination of trimethylamine-<i>N</i>-oxide and trimethylamine contents in nine commercially available liquid fish oils and three commercially available fish oil capsules, showing that trimethylamine and trimethylamine-<i>N</i>-oxide are not present in highly refined fish oils.
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spelling doaj.art-022dadbec0a5441ea5955ee47a27a5952024-03-27T13:57:06ZengMDPI AGMolecules1420-30492024-03-01296133910.3390/molecules29061339Quantification of Trimethylamine-<i>N</i>-Oxide and Trimethylamine in Fish Oils for Human ConsumptionDominik Dörfel0Sascha Rohn1Eckard Jantzen2GALAB Laboratories GmbH, Am Schleusengraben 7, 21029 Hamburg, GermanyDepartment of Food Chemistry and Analysis, Institute of Food Technology and Food Chemistry, Technical University Berlin, Gustav-Meyer-Allee 25, 13355 Berlin, GermanyGALAB Laboratories GmbH, Am Schleusengraben 7, 21029 Hamburg, GermanySupplementing fish oil is one of the strategies to reduce the risk of cardiovascular disease, the leading cause of death around the world. Contradictorily, fish oil may also contain trimethylamine-<i>N</i>-oxide, a recently emerged risk factor for cardiovascular disease, as well as one of its precursors, trimethylamine. A method suitable for routine quantification of trimethylamine-<i>N</i>-oxide and trimethylamine in fish oil with a quick and easy liquid extraction without derivatization has been developed. Liquid chromatography with tandem mass spectrometry detection was employed along with a zwitterionic hydrophilic interaction liquid chromatography column and a gradient elution with eluents containing 50 mmol/L of ammonium formate. An internal standard (triethylamine) was used for quantification by mass spectrometry with an external calibration. The assay proved high linearity in the ranges of 10 to 100 ng/mL and 100 to 1000 ng/mL for trimethylamine-<i>N</i>-oxide and trimethylamine, respectively. The lowest limit of quantification was determined to be 100 µg/kg for trimethylamine and 10 µg/kg for trimethylamine-<i>N</i>-oxide, with the limit of detection at 5 µg/kg and 0.25 µg/kg, respectively. Accuracy ranged from 106–119%. Precision was below 7% the relative standard deviation for both analytes. The method was successfully applied for the determination of trimethylamine-<i>N</i>-oxide and trimethylamine contents in nine commercially available liquid fish oils and three commercially available fish oil capsules, showing that trimethylamine and trimethylamine-<i>N</i>-oxide are not present in highly refined fish oils.https://www.mdpi.com/1420-3049/29/6/1339trimethylamine-<i>N</i>-oxidetrimethylaminefish oilHILIC-MS/MScardiovascular diseaseliquid extraction
spellingShingle Dominik Dörfel
Sascha Rohn
Eckard Jantzen
Quantification of Trimethylamine-<i>N</i>-Oxide and Trimethylamine in Fish Oils for Human Consumption
Molecules
trimethylamine-<i>N</i>-oxide
trimethylamine
fish oil
HILIC-MS/MS
cardiovascular disease
liquid extraction
title Quantification of Trimethylamine-<i>N</i>-Oxide and Trimethylamine in Fish Oils for Human Consumption
title_full Quantification of Trimethylamine-<i>N</i>-Oxide and Trimethylamine in Fish Oils for Human Consumption
title_fullStr Quantification of Trimethylamine-<i>N</i>-Oxide and Trimethylamine in Fish Oils for Human Consumption
title_full_unstemmed Quantification of Trimethylamine-<i>N</i>-Oxide and Trimethylamine in Fish Oils for Human Consumption
title_short Quantification of Trimethylamine-<i>N</i>-Oxide and Trimethylamine in Fish Oils for Human Consumption
title_sort quantification of trimethylamine i n i oxide and trimethylamine in fish oils for human consumption
topic trimethylamine-<i>N</i>-oxide
trimethylamine
fish oil
HILIC-MS/MS
cardiovascular disease
liquid extraction
url https://www.mdpi.com/1420-3049/29/6/1339
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