title: A novel multi-commutated method for the determination of hydroxytyrosol in enriched foods using mercaptopropionic acid-capped CdTe quantum dots.
abstract: Hydroxytyrosol (HXT) has been reported to have beneficial effects for human health, such as antioxidant and antimicrobial properties and an important contribution to the prevention of cardiovascular disease. Hence, exhaustive research is currently being performed to prepare functional foods, such as tomato juice or milk, with HXT. This paper presents a multi-commutated flow method based on the quenching effect that HXT has on the fluorescence of water-soluble mercaptopropionic acid-capped CdTe quantum dots. Under optimal conditions a linear working range was obtained for concentrations between 10 and 250 ng µl⁻¹. In order to demonstrate the suitability of the proposed method for the determination of HXT, HXT-enriched samples were prepared. Using a QuEChERS (quick, easy, cheap, effective, rugged and safe) procedure for extraction, HXT was determined in the prepared functional foods (milk, infant formula, tomato juice and tomato soup). Recoveries of 100% ± 8%, relative standard deviations (RSDs) lower than 5% and high sample throughput of 70 samples per h show the potential of the system for the analysis of HXT in food samples.
authors.affiliation: a Department of Physical and Analytical Chemistry, Faculty of Experimental Sciences , University of Jaén , Campus las Lagunillas, E-23071 Jaén , Spain.
authors.forename: E J
authors.initials: EJ
authors.lastname: Llorent-Martínez
authors.forename: L
authors.initials: L
authors.lastname: Molina-García
authors.forename: M L
authors.initials: ML
authors.lastname: Fernández-de Córdova
authors.forename: J L M
authors.initials: JL
authors.lastname: Santos
authors.forename: S S M
authors.initials: SS
authors.lastname: Rodrigues
authors.forename: A
authors.initials: A
authors.lastname: Ruiz-Medina
mesh_terms: D015097:3-Mercaptopropionic Acid / Q000737:chemistry; D000890:Anti-Infective Agents / Q000032:analysis*; D000975:Antioxidants / Q000032:analysis*; D057205:Automation, Laboratory; D019187:Cadmium Compounds / Q000737:chemistry*; D002851:Chromatography, High Pressure Liquid; D005513:Food Inspection / Q000379:methods*; D005527:Food, Fortified / Q000032:analysis*; D057166:High-Throughput Screening Assays; D007202:Indicators and Reagents / Q000737:chemistry; D057230:Limit of Detection; D010626:Phenylethyl Alcohol / Q000031:analogs & derivatives* / Q000032:analysis; D011786:Quality Control; D045663:Quantum Dots / Q000737:chemistry; D015203:Reproducibility of Results; D013050:Spectrometry, Fluorescence; D013499:Surface Properties; D013691:Tellurium / Q000737:chemistry*
chemical_list: D000890:Anti-Infective Agents; D000975:Antioxidants; D019187:Cadmium Compounds; D007202:Indicators and Reagents; C005975:3,4-dihydroxyphenylethanol; D015097:3-Mercaptopropionic Acid; D010626:Phenylethyl Alcohol; D013691:Tellurium; C028337:cadmium telluride