title: Tackling the challenge of selective analytical clean-up of complex natural extracts: the curious case of chlorophyll removal.
abstract: Alkaline saponification is often used to remove interfering chlorophylls and lipids during carotenoids analysis. However, saponification also hydrolyses esterified carotenoids and is known to induce artifacts. To avoid carotenoid artifact formation during saponification, Larsen and Christensen (2005) developed a gentler and simpler analytical clean-up procedure involving the use of a strong basic resin (Ambersep 900 OH). They hypothesised a saponification mechanism based on their Liquid Chromatography-Photodiode Array (LC-PDA) data. In the present study, we show with LC-PDA-accurate mass-Mass Spectrometry that the main chlorophyll removal mechanism is not based on saponification, apolar adsorption or anion exchange, but most probably an adsorption mechanism caused by H-bonds and dipole-dipole interactions. We showed experimentally that esterified carotenoids and glycerolipids were not removed, indicating a much more selective mechanism than initially hypothesised. This opens new research opportunities towards a much wider scope of applications (e.g. the refinement of oils rich in phytochemical content).
authors.affiliation: Flemish Institute for Technological Research (VITO), Business Unit Separation and Conversion Technology (SCT), Boeretang 200, 2400 Mol, Belgium; University of Antwerp, NatuRA, Universiteitsplein 1, 2610 Antwerp, Belgium. Electronic address: sebastiaan.bijttebier@vito.be.
authors.forename: Sebastiaan
authors.initials: S
authors.lastname: Bijttebier
authors.affiliation: Flemish Institute for Technological Research (VITO), Business Unit Separation and Conversion Technology (SCT), Boeretang 200, 2400 Mol, Belgium. Electronic address: els.dhondt@vito.be.
authors.forename: Els
authors.initials: E
authors.lastname: D'Hondt
authors.affiliation: Flemish Institute for Technological Research (VITO), Business Unit Separation and Conversion Technology (SCT), Boeretang 200, 2400 Mol, Belgium. Electronic address: bart.noten@vito.be.
authors.forename: Bart
authors.initials: B
authors.lastname: Noten
authors.affiliation: University of Antwerp, NatuRA, Universiteitsplein 1, 2610 Antwerp, Belgium. Electronic address: nina.hermans@uantwerpen.be.
authors.forename: Nina
authors.initials: N
authors.lastname: Hermans
authors.affiliation: University of Antwerp, NatuRA, Universiteitsplein 1, 2610 Antwerp, Belgium. Electronic address: sandra.apers@uantwerpen.be.
authors.forename: Sandra
authors.initials: S
authors.lastname: Apers
authors.affiliation: Flemish Institute for Technological Research (VITO), Business Unit Separation and Conversion Technology (SCT), Boeretang 200, 2400 Mol, Belgium. Electronic address: stefan.voorspoels@vito.be.
authors.forename: Stefan
authors.initials: S
authors.lastname: Voorspoels
mesh_terms: D000327:Adsorption; D002338:Carotenoids / Q000032:analysis; D002734:Chlorophyll / Q000302:isolation & purification*; D006017:Glycolipids / Q000032:analysis; D013058:Mass Spectrometry; D010936:Plant Extracts / Q000032:analysis*; D012116:Resins, Plant / Q000737:chemistry
chemical_list: D006017:Glycolipids; D010936:Plant Extracts; D012116:Resins, Plant; D002734:Chlorophyll; D002338:Carotenoids
keywords: Ambersep 900 OH; Carotenoids; Chlorophyll a (PubChem CID: 6477652); Citranaxanthin (PubChem CID: 6436724); Diacylglycerol (16:0/16:1) (PubChem CID: 9543678); Fucoxanthin (PubChem CID: 5281239); High valuable oils; LC-PDA–am-MS; Saponification; Selective chlorophyll removal mechanism; Triacylglycerol (16:0/16:1/16:1) (PubChem CID: 9543987); trans-β-Apo-8′-carotenal (PubChem CID: 5478003)