1,721,094 research outputs found
Characterization of the aromatic composition of commercial tannin samples by gas-chromatography- mass spectrometry
No full textQuechers extraction and a straightforward clean-up procedure for the quantification of polycyclic aromatic hydrocarbons (PAHS) in ripened cheese using GC-MS/MS
No full textPolycyclic Aromatic Hydrocarbons (PAHs) are chemicals made up of hydrogen and carbon atoms arranged in two or more fused aromatic rings. Over a hundred different PAH compounds exist, typically in complex mixtures. These compounds are known environmental carcinogens and can originate from both human activities and food processing. For non-smokers, the primary route of PAH exposure is through food consumption. Due to their lipophilic nature, PAHs can easily accumulate in fatty food matrices such as milk, meat, edible oils, fish, and cheese. This study aimed to develop an effective and straightforward sample preparation procedure for the determination of PAHs in ripened cheese samples. For this study, 60 samples of non-smoked hard cheese were collected from the market. The optimized protocol for PAH quantification consisted of three steps: 1) a rapid QuEChERS extraction using cyclohexane as the solvent, 2) a quick and efficient mechanical clean-up with Silica Gel (70-200 mesh ASTM), and 3) concentration under a gentle stream of nitrogen. PAH analysis was performed using an Agilent Intuvo 9000 GC system coupled with an Agilent 7000 Series Triple Quadrupole MS, employing a HP-5MS Ultra Inert capillary column (30 m × 0.32 mm id × 0.25 μm film thickness). Chromatograms were acquired in selected-ion monitoring (SIM) mode, and target compounds were identified based on their ions and retention times. Eighteen different PAHs were considered for method development: naphthalene (NaP), 2-methylnaphthalene (MeNaP2), 1-methylnaphthalene (MeNaP1), acenaphthene (Ace), acenaphthylene (Acp), fluorene (Flu), phenanthrene (Phen), anthracene (Ant), fluoranthene (Fla), pyrene (Pyr), benzo[a]anthracene (B[a]a), chrysene (Chr), benzo[b]fluoranthene (B[b]f), benzo[k]fluoranthene (B[k]f), benzo[a]pyrene (B[a]p), indeno[1,2,3-c,d]pyrene (I[cd]p), dibenzo[a,h]-anthracene (D[ah]a), and benzo[g,h,i]perylene (B[ghi]P). Once validated for linearity, repeatability, reproducibility, recovery, limit of detection (LOD), and limit of quantification (LOQ), the method was applied to analyze the entire set of collected samples. In three cheese samples were identified and quantified the lower molecular weight PAHs: NaP, MeNaP2 and MeNaP1. However, the degree of contamination in these samples was very low, with the total concentration not higher than 30 μg/kg. The experiments conducted in this study demonstrated that the proposed method effectively clean-up the sample while achieving acceptable recoveries, repeatability, and reproducibility for PAH quantification in cheese. Therefore, this method could be successfully applied to different food matrices with high fat content
Mass spectrometry in the characterization of ambers. II. Free succinic acid in fossil resins of different origin
No full textBaltic amber contains high levels of succinic acid, most of which is part of the polymer framework, and only recently has the presence of microcrystals of free succinic acid been documented by scanning electron microscopy and X-ray diffraction analysis. The determination of succinic acid can be used for an easy identification of Baltic amber among other fossil resins and to distinguish it from imitations, widely diffused on the market, produced with natural or modified recent or sub-fossil resins, such as copals. We report here a simple method, based on negative ion electrospray ionization mass spectrometry, for evaluating the free succinic acid content in water/methanol extracts of ambers from different origin, using a sample of about 20 mg. The limit of quantification is better than 1 ppm and, when applied to a set of amber samples of different origin, it was able to distinguish those of Baltic origin (showing free succinic acid levels in the range 50-400 ppm) from the others (for which succinic acid was undetectable, i.e. at levels lower than 1 ppm)
QuEChERS extraction and simple clean-up procedure for the GC-MS/MS quantification of polycyclic aromatic hydrocarbons (PAHs) in cheese
No full textPolycyclic Aromatic Hydrocarbons (PAHs) are chemical compounds associated with risks to human health, especially carcinogenesis. PAHs in food originate from environmental deposits or arise from food processing. In this study a fast and effective method to quantify PAHs in difficult fatty food matrices, such as cheese, was propose
Impact of several 2017 commercial yeasts in the aroma volatiles profile of white wines
No full textEight yeasts (Anchor Yeast Vin13, Blastosel FR95, AEB Fermol Arome Plus, Lamothe Abiet Excellence STR, Anchor Yeast Alchemy II, La Claire EM2, Vason Premium Chardonnay, Laffort Zymaflore VL3) were used for the fermentation of 7 different white juices, and the relevant wines were analysed by GC-MS/MS. Significant differences were observed between yeasts in wine composition as regards: basic parameters (with the exception of alcohol), higher alcohols, acetaldehyde, ethyl acetate, acetates and esters, C6 alcohols, 2- phenylethanol, metionol, benzyl alcohol, and short- and middle-chain fatty acid
Development of a fast Gas Chromatography Tandem Mass Spectrometry method for VOCs analysis in oenological products
No full text- …
