title: Development and Validation of New Ultra-High-Performance Liquid Chromatography-Hybrid Quadrupole-Orbitrap Mass Spectrometry Method for Determination of Melatonin in Fruits.
abstract: A new reliable analytical method based on ultra-high-performance liquid chromatography coupled with hybrid quadrupole-Orbitrap mass spectrometry was developed for the analysis of melatonin (MEL) in food products. In-house validation was performed using deuterated melatonin (MEL-d4) as an internal standard to ensure method selectivity and accuracy and to evaluate the efficiency of a robust ethyl acetate extraction technique used for sample preparation. The analysis of 18 tart cherry varieties and 28 tomato varieties was performed at optimized conditions. The method was linear (R(2)> 0.99) over the concentration range of 5-200 pg/g. A very low limit of quantification (10 pg/g) was provided for both analyzed matrices. The determined average recoveries (102 and 110%) and the values of intraday repeatability (6.30 and 10.9%) for cherry and tomato matrices, respectively, indicated a good accuracy and precision. The elaborated procedure proved the absence of MEL in any of tart cherries (<10 pg/g), whereas the concentration levels in tomatoes were found to be in the range of <10-149 pg/g, where the highest concentrations were determined in "Cherry," "Cherry Red" and "Rome" tomatoes grown in the Netherlands.
authors.affiliation: Institute of Food Safety, Animal Health and Environment "BIOR", Lejupes iela 3, Riga LV-1076, Latvia ingars.reinholds@bior.lv.
authors.forename: Ingars
authors.initials: I
authors.lastname: Reinholds
authors.affiliation: Institute of Food Safety, Animal Health and Environment "BIOR", Lejupes iela 3, Riga LV-1076, Latvia.
authors.forename: Iveta
authors.initials: I
authors.lastname: Pugajeva
authors.affiliation: Latvia State Institute of Fruit-Growing, Graudu iela 1, Dobele LV-3701, Latvia.
authors.forename: Vitalijs
authors.initials: V
authors.lastname: Radenkovs
authors.affiliation: Institute of Food Safety, Animal Health and Environment "BIOR", Lejupes iela 3, Riga LV-1076, Latvia.
authors.forename: Jekaterina
authors.initials: J
authors.lastname: Rjabova
authors.affiliation: Institute of Food Safety, Animal Health and Environment "BIOR", Lejupes iela 3, Riga LV-1076, Latvia.
authors.forename: Vadims
authors.initials: V
authors.lastname: Bartkevics
mesh_terms: D002851:Chromatography, High Pressure Liquid; D005504:Food Analysis / Q000379:methods*; D005638:Fruit / Q000737:chemistry*; D057230:Limit of Detection; D008550:Melatonin / Q000032:analysis*; D015203:Reproducibility of Results; D053719:Tandem Mass Spectrometry
chemical_list: D008550:Melatonin