title: Graphene/TiO2 nanocomposite based solid-phase extraction and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry for lipidomic profiling of avocado (Persea americana Mill.).
abstract: Phospholipids possess important physiological, structural and nutritional functions in biological systems. This study described a solid-phase extraction (SPE) method, employing graphene and titanium dioxide (G/TiO2) nanocomposite as sorbent, for the selective isolation and enrichment of phospholipids from avocado (Persea americana Mill.). Based on the principal that the phosphoryl group in the phospholipid can interact with TiO2 via a bridging bidentate mode, an optimum condition was established for SPE, and was successfully applied to prepare avocado samples. The extracts were monitored by matrix-assisted laser desorption ionization time-of-flight/tandem mass spectrometry (MALDI-TOF/MS) in both positive-ion and negative-ion modes. Results showed that phospholipids could be efficiently extracted in a clean manner by G/TiO2 based SPE. In addition, the signals of phospholipids were enhanced while the noise was reduced. Some minor peaks became more obvious. In conclusion, the nanocomposite material of G/TiO2 was proved to be a promising sorbent for selective separation of phospholipids from crude lipid extract.
authors.affiliation: Department of Biomedical Sciences, City University of Hong Kong, 83 Tat Chee Avenue, Kowloon, Hong Kong SAR, China.
authors.forename: Qing
authors.initials: Q
authors.lastname: Shen
authors.affiliation: Department of Biomedical Sciences, City University of Hong Kong, 83 Tat Chee Avenue, Kowloon, Hong Kong SAR, China.
authors.forename: Mei
authors.initials: M
authors.lastname: Yang
authors.affiliation: Department of Biomedical Sciences, City University of Hong Kong, 83 Tat Chee Avenue, Kowloon, Hong Kong SAR, China.
authors.forename: Linqiu
authors.initials: L
authors.lastname: Li
authors.affiliation: Department of Biomedical Sciences, City University of Hong Kong, 83 Tat Chee Avenue, Kowloon, Hong Kong SAR, China. Electronic address: bhhonyun@cityu.edu.hk.
authors.forename: Hon-Yeung
authors.initials: HY
authors.lastname: Cheung
mesh_terms: D006108:Graphite / Q000737:chemistry*; D053761:Nanocomposites / Q000737:chemistry*; D027421:Persea / Q000737:chemistry*; D010743:Phospholipids / Q000032:analysis* / Q000302:isolation & purification; D052616:Solid Phase Extraction / Q000379:methods*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods; D014025:Titanium / Q000737:chemistry*
chemical_list: D010743:Phospholipids; C009495:titanium dioxide; D006108:Graphite; D014025:Titanium
keywords: Avocado; Graphene/TiO(2); Lipidomics; MALDI-TOF/MS; Principal component analysis; Solid-phase extraction