Carnitine analysis in food and biological samples: Chromatography and mass spectrometry insights

Carnitines, essential for human metabolism and fatty acid transport, are primarily obtained from the diet. Inadequate synthesis or intake can lead to serious metabolic disorders, which may result in fatal outcomes. Therefore, the accurate determination of carnitines in both food and biological samples is of high importance. However, these samples are inherently complex and require meticulous preparation procedures before determination. This step is critical for enhancing the sensitivity and precision of the detection process. Moreover, the selection of an appropriate detection method is crucial and must match the analytes' characteristics. For example, since carnitines lack chromophores for spectroscopic detection, they require derivatization to become spectroscopically visible. Among the various methods available for carnitine determination, chromatography and mass spectrometry are the most prominent, owing to their superior selectivity and sensitivity. Nonetheless, there seems to be a lack of comprehensive reviews on this subject. Consequently, this article aims to compile the latest advancements in analytical methodologies for carnitines over the past decade (2013-2023), with a particular emphasis on the crucial contributions of chromatography and mass spectrometry techniques. This review provides crucial insights for metabolic research, underpinning advances in understanding carnitine's metabolic roles. It aims to highlight current innovations in carnitine analysis and inspire future breakthroughs impacting nutrition, diagnostics, and therapy.