title: Determination of N-nitrosamines in processed meats by liquid extraction combined with gas chromatography-methanol chemical ionisation/mass spectrometry.
abstract: A simple, accessible and reproducible method was developed and validated as an alternative for the determination of nine volatile N-nitrosamines (NAs) in meat products, using a low volume of organic solvent and without requiring specific apparatus, offering the possibility of practical implementation in routine laboratories. The NAs were extracted with dichloromethane followed by a clean-up with phosphate buffer solution (pH 7.0). The extracts were analysed by gas chromatography-chemical ionisation/mass spectrometry (GC-CI/MS) in positive-ion mode using methanol as reagent. Limits of detection and quantification, recovery and reproducibility were determined for all NAs (N-nitrosodimethylamine, N-nitrosomethylethylamine, N-nitrosodiethylamine, N-nitrosopyrrolidine, N-nitrosodipropylamine, N-nitrosomorpholine, N-nitrosopiperidine, N-nitrosodibutylamine and N-nitrosodiphenylamine). Satisfactory sensitivity and selectivity were obtained even without concentrating the extract by solvent evaporation, avoiding the loss of the nine NAs studied. Limits of detection ranged from 0.15 to 0.37 µg kg(-1), whereas limits of quantification ranged from 0.50 to 1.24 µg kg(-1). Recoveries calculated in cooked ham that had been spiked at 10 and 100 µg kg(-1) were found to be between 70% and 114% with an average relative standard deviation of 13.2%. The method was successfully used to analyse five samples of processed meat products on the day of purchase and 7 days later (after storage at 4°C). The most abundant NAs found in the analysed products were N-nitrosodipropylamine and N-nitrosopiperidine, which ranged from 1.75 to 34.75 µg kg(-1) and from 1.50 to 4.26 µg kg(-1), respectively. In general, an increase in the level of NAs was observed after the storage period. The proposed method may therefore be a useful tool for food safety control once it allows assessing the profile and the dietary intake of NAs in food over time.
authors.affiliation: a Department of Food Science and Technology , Universidade Federal de Santa Maria , Santa Maria , Rio Grande do Sul , Brazil.
authors.forename: Marina Bergoli
authors.initials: MB
authors.lastname: Scheeren
authors.forename: Hassan
authors.initials: H
authors.lastname: Sabik
authors.forename: Claude
authors.initials: C
authors.lastname: Gariépy
authors.forename: Nelcindo Nascimento
authors.initials: NN
authors.lastname: Terra
authors.forename: Joseph
authors.initials: J
authors.lastname: Arul
mesh_terms: D005503:Food Additives / Q000032:analysis*; D008401:Gas Chromatography-Mass Spectrometry; D008461:Meat Products / Q000032:analysis*; D000432:Methanol / Q000737:chemistry*; D008752:Methylene Chloride / Q000737:chemistry; D009602:Nitrosamines / Q000032:analysis*; D010710:Phosphates / Q000737:chemistry; D012996:Solutions
chemical_list: D005503:Food Additives; D009602:Nitrosamines; D010710:Phosphates; D012996:Solutions; D008752:Methylene Chloride; D000432:Methanol
keywords: N-nitrosamines; gas chromatography/mass spectrometry; liquid extraction; meat products; methanol chemical ionisation