Collision Cross-Section Determination and Tandem Mass Spectrometric Analysis of Isomeric Carotenoids Using Electrospray Ion Mobility Time-of-Flight Mass Spectrometry

Abstract

Carotenoids are natural pigments with provitamin A and antioxidant activities. Biosynthesized in plants as their all-trans isomers, carotenoids isomerize in solution and in humans to multiple cis isomers which can have different bioavailabilities and functions. Since separation and characterization of isomeric carotenoids using HPLC or LC-MS-MS is time consuming, the potential for ion mobility mass spectrometry (IM-MS) to resolve and characterize carotenoid isomers rapidly without chromatography was investigated using travelling-wave ion mobility spectrometry on a quadrupole time-of-flight mass spectrometer. The all-trans isomers of lycopene and β-carotene were separated by several milliseconds from the cis-isomers which were detected as partially overlapping peaks. The collision cross-section values of these carotenoid isomers were determined using IM-MS to be 180 Å2 and 236 Å2 for cis-lycopenes and all-trans-lycopene, and 181 Å2 and 225 Å2 for cis-β-carotene and all-trans-β-carotene, respectively. Collision-induced dissociation MS-MS of ion mobility-resolved isomers indicated that cis and all-trans carotenoid isomers can be distinguished by their fragmentation patterns. Previous MS-MS studies of cis- and all trans-carotenoids had suggested that they produced identical tandem mass spectra, but this appears to have been the result of isomerization during ionization. Introduction of specific cis or trans isomers by infusion or HPLC resulted in cis/trans isomerization in the ion source during electrospray, and the relative levels of cis carotenoids forming in the ion source compared to the all-trans isomers were temperature dependent.

Extraction and Analysis of the Major Carotenoids of Agro-Industrial Waste Materials Using Sequential Extraction Techniques and High Performance Liquid Chromatography

“…Much effort has been devoted to developing HPLC-mass spectrometry (HPLC-MS) methods with mainly atmospheric pressure ionization interfaces (APCI) or electrospray ionization interfaces (ESI) [30]. Also, capillary electrophoresis (CE) [31], high 3 performance thin layer chromatography (HPTLC), ultraviolet-visible (UV-Vis), infrared (IR) and Raman spectrometry have been employed as an analytical technique to identify and quantify low levels and various forms of carotenoids [21,[32][33][34].…”

Metabolomics of carotenoids: The challenges and prospects – A review

“…This technique provides an opportunity to determine carotenoid geometrical isomers based on its fragmentation pattern formed during CID. Dong et al (2010) characterized the geometrical carotenoid isomers using travelling-wave ion mobility spectrometry on a quadrupole time-of-flight mass spectrometer. However, various cis isomers cannot be resolved by using IMS.…”

10years of MS instrumental developments – Impact on LC–MS/MS in clinical chemistry

“…Since separation and characterization of isomeric carotenoids using HPLC or LC-MS/MS is time-consuming, the potential of IMMS to resolve and characterize carotenoid isomers rapidly without chromatography was investigated using TWIMS on a QTOF mass spectrometer [135]. The all-trans isomers of lycopene and ␤-carotene were separated by several milliseconds from the cis isomers which were detected as partially overlapping peaks.…”