Quantitative profiling of retinyl esters in milk from different ruminant species by using high performance liquid chromatography-diode array detection-tandem mass spectrometry.
An effective high performance liquid chromatography-diode array detection-tandem mass spectrometry (HPLC-DAD-MS/MS) analytical approach was developed for retinoid profiling in raw milk samples (cow, buffalo, ewe, and goat). The analytes were isolated by means of liquid-liquid extraction, including a "lipid freezing" step, with yields exceeding 66%. Since the positive atmospheric pressure chemical ionisation mass spectrometry (APCI-MS) detection is not completely selective, a reliable identification has been accomplished by fully separating the analytes on a tandem C18/C30 column system under non-aqueous reversed phase (NARP) chromatography conditions. After validation, different milk varieties obtained from pasture-fed animals were analysed, providing, for the first time, the retinoid composition of both buffalo's and ewe's milk. According to the literature, retinyl palmitate has been found to be the most abundant vitamin A vitamer, but retinyl oleate is the prevalent form in the caprine milk.
Institute of Chemical Methodologies, Italian National Research Council, Area della Ricerca di Roma I, Via Salaria km 29, 300-00015 Monterotondo, Rome, Italy.
Silvia
S
Rocchi
Department of Chemistry, Faculty of Mathematical, Physical and Natural Sciences, University of Rome "La Sapienza", P.le Aldo Moro 5, 00185 Rome, Italy. Electronic address: fulvia.caretti@uniroma1.it.
Fulvia
F
Caretti
Department of Chemistry, Faculty of Mathematical, Physical and Natural Sciences, University of Rome "La Sapienza", P.le Aldo Moro 5, 00185 Rome, Italy.
Alessandra
A
Gentili
Department of Chemistry, Faculty of Mathematical, Physical and Natural Sciences, University of Rome "La Sapienza", P.le Aldo Moro 5, 00185 Rome, Italy.
Roberta
R
Curini
Department of Chemistry, Faculty of Mathematical, Physical and Natural Sciences, University of Rome "La Sapienza", P.le Aldo Moro 5, 00185 Rome, Italy.
Daniela
D
Perret
Department of Analytical Chemistry, Physical Chemistry and Chemical Engineering, Faculty of Chemistry, University of Alcalá, Ctra.Madrid-Barcelona, km. 33.600, 28871 Alcalá de Henares (Madrid), Spain.
Virginia
V
Pérez-Fernández
D000818:Animals; D002417:Cattle; D056148:Chromatography, Reverse-Phase; D004224:Diterpenes; D004952:Esters / Q000032:analysis*; D005260:Female; D005504:Food Analysis; D006041:Goats; D057230:Limit of Detection; D059625:Liquid-Liquid Extraction; D008892:Milk / Q000737:chemistry*; D015203:Reproducibility of Results; D000084562:Retinyl Esters; D012756:Sheep; D053719:Tandem Mass Spectrometry; D014801:Vitamin A / Q000031:analogs & derivatives / Q000032:analysis
D004224:Diterpenes; D004952:Esters; D000084562:Retinyl Esters; D014801:Vitamin A; C014794:retinol palmitate; C042067:retinol oleate
HPLC-MS; Milk; Retinoids; Retinyl esters; Vitamin A; Vitamin A vitamers profiling