Fast Sample Preparation Method Using Ultra-High Performance Liquid Chromatography Coupled to Tandem Mass Spectrometry for Natamycin Determination in Wine Samples

Abstract

An easy and efficient sample preparation method was developed for the determination of natamycin residues in wine samples by solvent extraction and ultra-high performance liquid chromatography coupled to tandem mass spectrometry (UHPLC-MS/MS) analysis. After choosing acetonitrile as extraction solvent, an experimental design was carried out with different amounts of C18 and primary secondary amine (PSA) sorbents in order to optimize the clean-up step. Validation results were satisfactory, with recoveries from 77 to 95% and relative standard deviation (RSD) lower than 10% for the spike levels 5, 10 and 20 µg L , respectively. The validated method proved to be an excellent analytical tool, with a total analysis time of 3 min. The method was applied in 10 Brazilian wine samples and no residues of natamycin were detected. Keywords: natamycin, wine, sample preparation, UHPLC-MS/MS IntroductionThe use of preservatives in food and beverages is necessary to prevent or retard microbial growth avoiding undesirable alterations in the final product quality. Among the antimicrobial substances employed by the food industry, natamycin has been proven an effective alternative for controlling microbial growth.1 Natamycin or pimaricin is an antibiotic belonging to the group of polyene macrolides produced by actinomycetes Streptomyces natalensis. 2,3 Several studies reported the use of natamycin for the surface treatment of cheeses and dry sausages [4][5][6] and most recently, in antimicrobial packaging systems. 7 Natamycin cannot be added to wines because it is classified as a non-permitted additive by the Code of Enological Practices of the International Organization of Vine and Wine (OIV). ) where it is used as an alternative to sulfur dioxide during bottling, preventing refermentation in sweet and low acidity wines. 9 However, export wines must comply with EU standards and currently a level of 5 µg L -1 is enforced in countries as Germany. 10 Recently, the European disease control authorities detected natamycin in wine samples from different producing countries and banned their sale and distribution. 11,12 Besides addition to the wine, many wineries use natamycin on the walls and floors to eliminate the yeast and mold in the environment. Under these conditions, natamycin can be transferred into the wine being a contamination source.In Brazil, the Brazilian Health Regulatory Agency (ANVISA) did not authorize the use of natamycin in wines, only on cheese surface with a maximum limit of 2 mg per 100 cm 2 and meat surface of embedded products with a maximum limit of 1 mg per dm 2 . 13 However, even the use of this not authorized compound, in the last years several wine samples were confiscated from Brazilian wineries due to the use of natamycin.14 Generally, the analytical methods for natamycin determination in food and beverages samples use organic solvents for extraction followed by filtration and determination by liquid chromatography. Roberts et al. 15 developed a rapid procedure based on liquid chromatography coupled to hig...

Development and application of a liquid chromatography-mass spectrometry method for the determination of sugars and organics acids in araza, ceriguela, guava, mango and pitanga

“…However, Brasil (2017) establishes that the use of alternative approaches for the validation of analytical methods applied to biological products will be admitted and that the use of a method with technical limitations to determine selectivity is accepted through technical justification. In this regard, Bernardi et al, (2016);Yang et al, 2015) demonstrated that the sample dilution (dilution factor 15 to 100) before injection into the LC-ESI MS/MS system is an easy and effective method to improve the selectivity of the method and to reduce or eliminate the matrix effect (effect on the analytical response induced by interfering compounds present in the matrix) (Bernardi et al, 2016). Thus, in this study, selectivity and elimination of the possible matrix effect was assessed by the dilution approach, since depending on the matrix and the analyte the samples were diluted (ranged between 10 to 400 times) to get in the linear range of the analytical curves.…”