Biomedical subjects

R Bortolomeazzi

Publications and source records attributed to R Bortolomeazzi.

5 recordsLinked to original sources

PubMed1995

Determination of polycyclic aromatic hydrocarbons in water and water-based alcoholic beverages.

This paper proposes a simple HPLC method for the determination of polycyclic aromatic hydrocarbons (PAHs) in water, wine and beer. Samples were purified by PAH collection in solid-phase extraction (SPE) and analysed by reversed-phase HPLC (Supelcosil LC-PAH column from Supelco). For the beer sample, recoveries amounted to 28% for naphthalene and varied from 57% to 103% for the other PAHs; results are quantitative starting from fluoranthene (FI, the seventh component eluted). Almost all the beer and wine samples showed the presence of benzo(b)fluoranthene (BbF), benzo(k)fluoranthene (BkF), benzo(a)pyrene (BaP), benz(ghi)perylene (BghiP) and indeno(1,2,3-cd)pyrene (IP), and in some cases there were traces of FI, benzo(a)anthracene (BaA) and dibenz(ah) anthracene (DBahA). Total contents of PAHs ranged from trace amounts to 0.72 ppb. Traces of BbF, BkF, BaP, BghiP and IP were also found in the wine samples.

Beer↗

PubMed1994

Identification of thermal oxidation products of cholesteryl acetate.

The polar products separated by solid-phase extraction from the peroxidation mixture of cholesteryl acetate, were investigated. The oxidation products were identified by comparing GC retention times as well as the mass spectra against those of available or synthesized standards. The main oxidation products where 7 beta-chydroperoxicholesteryl acetate, 7 alpha-hydroperoxicholesteryl acetate, 7-ketocholesteryl acetate, the alpha and beta isomers of 7-hydroxycholesteryl acetate, the alpha- and beta-epoxy isomers in 5,6 position and several derivatives from the loss of groups (especially the acetic and/or hydroxyl groups in the form of acetic acid and water).

Cholesterol Esters↗

PubMed1992

Improvement of extraction procedure for biogenic amines in foods and their high-performance liquid chromatographic determination.

A high-performance liquid chromatography method is described for the simultaneous determination of the biogenic amines tryptamine, 2-phenylethylamine, putrescine, cadaverine, histamine, tyramine, spermidine, and spermine in cheese. The optimization of the procedure for the extraction of amines from the matrix is described. The separation of dansyl derivatives of the amines was achieved by reversed-phase liquid chromatography with gradient elution, followed by UV detection at 254 nm. The mobile phase was acetonitrile-0.01 M phosphate buffer (pH 7)-water. Under these conditions, rapid elution of the amines in less than 13 min was obtained. Validation of the method included calibration experiments, addition of standard amines for the determination of amine recoveries and repeatability tests.

Biogenic Amines↗

PubMed1992

Cannabinoid acids analysis.

The cannabinoid pattern of vegetable preparations from Cannabis sativa (hashish, marijuana) allows to recognize the phenotype of the plants, to be used as drug or for fiber. Cannabinoid determination by analytical point of view has represented some problems caused by the complex composition of the hexane extract. Capillary gas chromatography of the hexane extracts of vegetable samples, shows the presence of rather polar constituents that eluted, with noticeable interactions, only on polar phase. The compounds can be methylated by diazomethane and silanized (TMS) by silylating reagents. The methyl and methyl-TMS derivatives are analyzed by high resolution gas chromatography (HRGC) and by gas chromatography-mass spectrometry (GC-MS). The identification of the compounds shows their nature of cannabinoid acids, which the main by quantitative point of view results the cannabidiolic acid (CBDA). It is known that the cannabinoid acids are thermally unstable and are transformed in the corresponding cannabinoids by decarboxilation. This is of interest in forensic analysis with the aim to establish the total amount of THC in the Cannabis preparations, as the active component.

Cannabinoids↗

PubMedDate not supplied

Oxisterol determination in selected coffees.

The main aim of green-coffee processing techniques, such as decaffeination and roasting, is always to maintain a very high level of quality in taste and flavor, the beverage's most important characteristics to consumers. Oxidative alterations of coffee lipids, which can occur in roasting, exert a very marked influence on these quality traits. Determining the extent of oxidation thus can provide an indication of the product's potential shelf-life and reveal traces of any newly-formed oxidative products that might prove nutritionally unsafe. Yet, while much attention has recently been focused on certain by-products induced by cholesterol oxidation and their proven toxicity as risk factors in atherosclerosis and cancer, oxidated phytosterols have largely gone unnoticed, being considered along with beta-sitosterol as not very dangerous in that neither is absorbed by the intestinal tract. The present study investigates the substances derived from phytosterol oxidation (oxisterols) in samples of regular and decaffeinated commercial coffees. The findings show that oxisterols were absent in some samples and that the traces of oxidate phytosterols detected in others were well below the threshold considered as toxicologically active.

Coffee↗