Multidimensional Analytical Approach Based on UHPLC-UV-Ion Mobility-MS for the Screening of Natural Pigments

Abstract

Here, we propose a novel strategy that combines a typical ultra high performance liquid chromatography (UHPLC), data-independent mass spectrometry (MS(E)) workflow with traveling wave ion mobility (TWIM) and UV detection, to improve the characterization of carotenoids and chlorophylls in complex biological matrices. UV detection selectively highlighted pigments absorbing at specific wavelengths, while TWIM coupled to MS was used to maximize the peak capacity. We applied this approach for the analysis of pigments in different microalgae samples, including Chlorella vulgaris, Dunaliella salina, and Phaeodactylum tricornutum. Using UHPLC-UV-MS(E) information (retention time, absorbance at 450 nm, and accurate masses of precursors and product ions), we tentatively identified 26 different pigments (carotenes, chlorophylls, and xanthophylls). By adding TWIM information (collision cross sections), we further resolved 5 isobaric pigments, not resolved by UHPLC-UV-MS(E) alone. The characterization of the molecular phenotypes allowed us to differentiate the microalgae species. Our results demonstrate that a combination of TWIM and UV detection with traditional analytical approaches increases the selectivity and specificity of analysis, providing a new tool to characterize pigments in biological samples. We anticipate that such an analytical approach will be extended to other lipidomics and metabolomics applications.

Untargeted Metabolomics Strategies—Challenges and Emerging Directions

“…With either a score or level-based system, the future of annotation is likely to be influenced by multiplexed technologies. Recently, Pacini et al obtained five levels of small molecule data in a single DIA acquisition (LC,UV, IM, MS, MS/MS) [31]. Advances of multidimensional analytical approaches are inherently the most promising for the broadest metabolome coverage.…”

Metabolic Profiling as a Screening Tool for Cytotoxic Compounds: Identification of 3-Alkyl Pyridine Alkaloids from Sponges Collected at a Shallow Water Hydrothermal Vent Site North of Iceland

“…We investigated the butanol fraction by using another LC-MS method, which combines a longer chromatographic run and data independent mass spectrometry (MS E ) [30]. The longer run was necessary to separate co-eluting 3-APA compounds, whilst the MS E approach was used because it enables the simultaneous collection of both unfragmented and fragmented ions by generating two discrete and independent interleaved acquisition functions [30,31]. The function 1 (low collision energy) provides unfragmented ions and accurate mass information, while the function 2 (high collision energy) provides fragmented ions.…”

Feasibility of ultra-performance liquid chromatography–ion mobility–time-of-flight mass spectrometry in analyzing oxysterols

“…The IM combined with LC-MS is also increasingly used in bioanalytics [32][33][34], because IM provides an additional degree of separation and thus significantly improved peak capacity and specificity. This can be particularly beneficial for example in the analysis of complex biological samples and in the separation of isomeric compounds [35,36].…”