Monday, July 11, 2016

A Derivative Method with Free Radical Oxidation to Predict Resveratrol Metabolites by Tandem Mass Spectrometry

Author(s):

Wangta Liu, Yow-Ling Shiue, Yi-Reng Lin, Hugo You-Hsien Lin and Shih-Shin LiangPages 300-306 (7)

Abstract:


In this study, we demonstrated an oxidative method with free radical to generate 3,5,4 -trihydroxy-transstilbene (trans-resveratrol) metabolites and detect sequentially by an autosampler coupling with liquid chromatography electrospray ionization tandem mass spectrometer (LC-ESI–MS/MS). In this oxidative method, the free radical initiator, ammonium persulfate (APS), was placed in a sample bottle containing resveratrol to produce oxidative derivatives, and the reaction progress was tracked by autosampler sequencing. Resveratrol, a natural product with purported cancer preventative qualities, produces metabolites including dihydroresveratrol, 3,4 -dihydroxy-trans-stilbene, lunularin, resveratrol monosulfate, and dihydroresveratrol monosulfate by free radical oxidation. Using APS free radical, the concentrations of resveratrol derivatives differ as a function of time. Besides simple, convenient and time- and labor saving, the advantages of free radical oxidative method of its in situ generation of oxidative derivatives followed by LC-ESI–MS/MS can be utilized to evaluate different metabolites in various conditions.

Keywords:

Free radical, metabolite, resveratrol, ammonium persulfate (APS), liquid chromatography tandem mass spectrometry (LC–MS/MS), multiple reaction monitoring (MRM).

Affiliation:

Department of Biotechnology, Kaohsiung Medical University, P.O. Box: 80708 Kaohsiung, Taiwan.


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Characterization study of tomato sauces stored in different packaging materials

Author(s):

Emilio Marengo, Eleonora Mazzucco, Elisa Robotti, Fabio Gosetti, Marcello Manfredi and Giorgio CalabresePages 1-1 (1)

Abstract:


BACKGROUND: In the last decades particular attention is devoted to packaging materials to obtain the better conditions to storage food and to preserve the organoleptic properties. METHODS: In the present study samples of tomato sauce collected in different Italian markets and preserved in different packaging materials (glass, tin and multilayer plastic containers) were chemically characterized considering the content of anions (6 species), carotenoids (lycopene, sum of alpha- and beta-carotene), flavonoids (epicatechin and quercetin), metals (41 species), total polyphenols, vitamins (C and of B-groups), and volatile profile. Different analytical techniques were employed like GC and LC with different detectors (MS and DAD), and ICP-MS and ICP-OES. All developed methods were validated and applied to different commercial products collected from local markets. RESULTS: Multivariate statistical tools (Principal Components Analysis – Discriminant Analysis, PCA – DA, Ranking PCA and Partial Least Square – Discriminant Analysis, PLS – DA) were then applied to evaluate the effect played by the different packaging on the chemical profile of the samples. The multivariate strategy adopted allowed to identify markers able to discriminate samples stored in glass, tin or multilayer plastic containers. CONCLUSION: In both cases, the differences identified between the classes of samples can be ascribed to a double effect: 1) products stored in glass preserve their content in vitamins and other important nutrients or 2) storage in glass could force manufacturers to provide a product of better quality since the product is visible to the final consumer.

Keywords:

Tomato sauce, characterization study, packaging material, multivariate statistical analysis.

Affiliation:

Department of Science and Technological Innovation, University of Piemonte Orientale, Viale Michel 11, 15121 Alessandria, Italy.


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Adsorption and Characterization of an Organic Corrosion Inhibitor for Inhibiting Carbon Steel Corrosion in Chloride Solution

Author(s):

Yu Lei, Liu Zhiyong, Yang Weibin and Wang ZixiaoPages 141-146 (6)

Abstract:


The adsorption and inhibition behaviors of an organic corrosion inhibitor (C12) on the surface of the carbon steel in chloride solution were systematically investigated by using electrochemical measurements. The results indicated that C12 exhibited inhibition and curative effects on the depassivation steel in the presence of chloride. The inhibition efficiency (IE) of C12 was also studied at different temperature. It was seen that the IE was enhanced with an increase in C12 concentration. The Gibbs free energy (ΔG) calculated based on the proposed isothermal adsorption formula for the adsorption process showed that the absorption of inhibitor on steel surface including stably chemisorption. XPS and AFM analyses suggested that after C12 being incorporated, the C12 molecular was tightly adsorbed on the steel surface, resulting in a dense layer formation. This study provides an insight into better understanding of corrosion inhibiting mechanism of C12 in the chloride solution.

Keywords:

Adsorption isotherm, carbon steel, inhibition mechanism, organic corrosion inhibitor, surface analyses.

Affiliation:

School of Civil Engineering, Yantai University, Yantai 264005, P.R. China.

Graphical Abstract:



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The Occurrence of Veterinary Pharmaceuticals in the Environment: A Review

Author(s):

Fabio Kaczala and Shlomo E. BlumPages 169-182 (14)

Abstract:


It is well known that there is a widespread use of veterinary pharmaceuticals and consequent release into different ecosystems such as freshwater bodies and groundwater systems. Furthermore, the use of organic fertilizers produced from animal waste manure has been also responsible for the occurrence of veterinary pharmaceuticals in agricultural soils. This article is a review of different studies focused on the detection and quantification of such compounds in environmental compartments using different analytical techniques. Furthermore, this paper reports the main challenges regarding veterinary pharmaceuticals in terms of analytical methods, detection/quantification of parent compounds and metabolites, and risks/toxicity to human health and aquatic ecosystems. Based on the existing literature, it is clear that only limited data is available regarding veterinary compounds and there are still considerable gaps to be bridged in order to remediate existing problems and prevent future ones. In terms of analytical methods, there are still considerable challenges to overcome considering the large number of existing compounds and respective metabolites. A number of studies highlight the lack of attention given to the detection and quantification of transformation products and metabolites. Furthermore more attention needs to be given in relation to the toxic effects and potential risks that veterinary compounds pose to environmental and human health. To conclude, the more research investigations focused on these subjects take place in the near future, more rapidly we will get a better understanding about the behavior of these compounds and the real risks they pose to aquatic and terrestrial environments and how to properly tackle them.

Keywords:

Animal husbandry, antibiotics, metabolites, veterinary pharmaceuticals, waste manure.

Affiliation:

Department of Biology and Environmental Sciences, Linnaeus University, Kalmar, Sweden.

Graphical Abstract:



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Enantiomeric Profiling of Chiral Pharmacologically Active Compounds in the Environment with the Usage of Chiral Liquid Chromatography Coupled with Tandem Mass Spectrometry

Author(s):

Dolores Camacho-Munoz, Bruce Petrie, Erika Castrignanò and Barbara Kasprzyk-HordernPages 303-314 (12)

Abstract:


The issue of drug chirality is attracting increasing attention among the scientific community. The phenomenon of chirality has been overlooked in environmental research (environmental occurrence, fate and toxicity) despite the great impact that chiral pharmacologically active compounds (cPACs) can provoke on ecosystems. The aim of this paper is to introduce the topic of chirality and its implications in environmental contamination. Special attention has been paid to the most recent advances in chiral analysis based on liquid chromatography coupled with mass spectrometry and the most popular protein based chiral stationary phases. Several groups of cPACs of environmental relevance, such as illicit drugs, human and veterinary medicines were discussed. The increase in the number of papers published in the area of chiral environmental analysis indicates that researchers are actively pursuing new opportunities to provide better understanding of environmental impacts resulting from the enantiomerism of cPACs.

Keywords:

Analysis, chiral chromatography, chiral drugs, environment, mass spectrometry, pharmaceuticals, wastewater.

Affiliation:

Department of Chemistry, University of Bath, P.O. Box: BA2 7AY, Bath, United Kingdom.


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