Special Issue "Chromatographic Techniques for Food and Environmental Samples"
A special issue of Separations (ISSN 2297-8739).
Deadline for manuscript submissions: 30 June 2018
During last few decades, massive industrial and agricultural development has been accompanied by the release of a great variety of contaminants to the environment. Such compounds, depending on their physicochemical properties, might be incorporated into the food chain, which represents an important public concern. Accordingly, authorities have established restrictions to protect our environment from potential harmful substances. It has made the development of analytical methodologies, mainly based on chromatographic techniques, able to detect and determine a wide variety of compounds at very low concentration levels, in both food and environmental samples, in a reliable and accurate manner, necessary.
We would like to invite colleagues to contribute with original research articles and reviews to the present Special Issue on the latest trends in chromatographic techniques for the analysis of contaminants in environmental and food samples, including recent advances in sample preparation.
Dr. Antonio Martin-Esteban
Dr. Esther Turiel
Manuscript Submission Information
Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All papers will be peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.
Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Separations is an international peer-reviewed open access quarterly journal published by MDPI.
Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 350 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.
The below list represents only planned manuscripts. Some of these manuscripts have not been received by the Editorial Office yet. Papers submitted to MDPI journals are subject to peer-review.
Title: Chromatographic Techniques in the Research Area of Lithium Ion Batteries: Current State of the Art
Authors: Sascha Nowak, Martin Winter
Abstract: Lithium ion batteries (LIBs) are widely used in modern consumer electronics and medical applications and LIBs are increasingly used for electric vehicles and hybrid electric vehicles. Besides relatively high manufacturing costs and a long charging time, the major drawback is the degradation of the cell constituents, which is called aging and which minimizes both storage lifetime and cycle lifetime. Due to the numerous aging effects, both from the individual constituents and their interactions, a myriad of instruments and methods are reported in literature for the investigation of these effects. Especially chromatographic methods are heavily applied for the analysis of ionic liquids and non-aqueous electrolytes. However, chromatographic methods are recently used to investigate the composition of electrode materials. In this review, we will give an overview about the current state of chromatographic methods which are applied in the context of lithium ion battery research.
Title: Determination of 2-thioxo-3-pyrrolidinecarbaldehyde in takuan-zuke by high-performance liquid chromatography with fluorescence detection after pre-column derivatization using 4-(N,N-dimethylaminosulfonyl)-7-hydrazino-2,1,3-benzoxadiazole
Author: Hiroki Matsuoka
Abstract: Takuan-zuke, or pickled radish root, is one of the traditional food in Japan. Dehydrated radish root is pickled in salt/or salty rice bran and salt-aging for several months. The color of radish turns from white to yellow in long-term salting aging process. We previously reported that the yellowing reaction is derived from radish isothiocyanate, and that it is nonenzymatically converted to a yellow compound by going through several steps of reaction. Among them, 2-thioxo-3-pyrrolidinecarbaldehyde (TPC), which has been identified as a primary decomposition product of radish isothiocyanate, is an important intermediate for yellowing reaction. However, since TPC is highly reactive compound, it was difficult to extract for quantitative analysis. In the derivatization method with 2, 4-dinitrophenylhydrazine which is widely used for aldehyde analysis, the reactant from TPC is unstable. In this study, a simple and sensitive derivatization method using 4-(N, N-dimethylaminosulfonyl)-7-hydrazino-2,1,3-benzoxadiazole (DBD-H) was applied to the determination of TPC.
Method: A highly reactive reagent, DBD-H react with aldehyde moiety of TPC in the presence of trifluoroacetic acid (TFA). DBD-TPC was analyzed by ODS-HPLC with fluorescence detection. For an optimization of reaction conditions, we studied using the following condition; reaction time, solvent concentration, TFA concentration, and the stability of DBD-TPC at 4 °C. (2) Quantitative analysis of TPC contained in lyophilized takuan-zuke sample was performed using optimized analysis method.
Title: Assessment, Validation and Application to Real Samples of a Rp-Hplc Method For The Determination of Steviol Glycosides in Stevia Rebaudiana Bertoni’s Leaves
Authors: N. Spano1, M. Ciulu1, M. I. Pilo1, V.M. Nurchi2, J. Lachowitz2, G. Sanna1
Affiliation: 1Dipartimento di Chimica e Farmacia, Università di Sassari, Via Vienna, 2 – 07100 Sassari, Italy
2Dipartimento di Scienze Chimiche e Geologiche,Cittadella Universitaria di Monserrato, 09042 Monserrato, Cagliari, Italy
Abstract: Stevia rebaudiana Bertoni is a branched shrub of the Asteraceae family native to the tropical areas of Northern and Southern America, nowadays widespread in many regions of the world. It has a significant economic value due to its high content of natural, dietetically valuable sweeteners in its leaves. They consist in steviol glycosides as stevioside and rebaudioside A, the most abundant among more than 30 compounds recognized in different Stevia genotypes. Hence, the qualitative and quantitative characterization of these compounds may be a useful tool to differentiate and valorize plants grown in various regions and conditions. This approach allows the individuation of promising genotype in terms of sweetners’ yield and/or nutraceutical value. In this contribution we propose a validated RP-HPLC procedure for the determinations of the principal steviol glycosides (i.e. stevioside, rebaudiosides A and C and dulcoside A) in Stevia leaves. Validation was accomplished in terms of limit of detection, limit of quantification, linearity, precision, and trueness. Finally, the method was tested with a number of real samples of fresh and dried Stevia leaves from different geographical origins.
Title: Comparison of separation of seed oil triglycerides containing isomeric conjugated octadecatrienoic acid moieties by reversed-phase HPLC
Author: Victor Deineka
Abstract: Relative retention analysis has been applied for the investigation of triglycerides (TG) retention of a broad set of plant seed oils with conjugated octadecatrienoic acids (CLnA) by reversed-phase HPLC. The subjects of investigation – TG of seed oils: Calendula officinalis, Catalpa ovata, Jacaranda mimosofolia, Centranthus ruber, Momordica charantia, Trichosanthes cucumerina, Punica granatum, Schinziophyton rautanenii, Thladiantha dubia, Valeriana officinalis, Vernicia montana. Isocratic elution mode separation maps revealed the sequence of retention times of the same types of TG to be constant for reasonable compositions of propanol-2 – acetonitrile mobile phases and Kromasil 100-5C18 stationary phases:
punicic (C18:39Z11E13Z) < jacaric (C18:38Z10E12Z) < α-eleostearic (C18:39E11E13Z) < catalpic (C18:39Z11E13E) < calendic (C18:38E10E12Z) < β-eleostearic (C18:39E11E13E) < all-E calendic (C18:38E10E12E) acids.
Migration of CH2-group from the inner part of the fatty acid moiety to the outer one leads to rise of solute retention by closed (but not the same) values of logarithms of retention capacity (logk) for any starting cis-trans stereoisomers. Exchange of stereo configurations in direction cis→trans also results in increase of retention being different for inner and outer cis-double bond. Thus, it was proved that it is possible to differentiate TG of complex composition with moieties of all natural CLnA by retention control accomplished by electronic spectra comparison though there exist only three types of electronic-vibrational spectra for seven isomeric CLnA. For each type of investigated seed oils the TG composition was estimated by group contribution (increment) approach, the proposal was confirmed by mass-spectrometric detection in APCI method. On the example of Diasphere 110-C18, Nucleosil 100-C18 and Lichrosphere 100 RP C18 stationary phases it has been shown that equations of relative retention found for Kromasil 100-5C18 stationary phase may be transferred into another one.
Title: Assessment, Validation and Application to Real Samples of a RP-HPLC Method for the Determination of Guayulins A, B, C and D in Guayule Shrub
Authors: N. Spano 1,*, P. Meloni1, I. Idda 1, A. Mariani 1, M. I. Pilo 1, V.M. Nurchi 2, J. Lachowitz 2, G. Sanna 1,*
1 Dipartimento di Chimica e Farmacia, Università di Sassari, Via Vienna, 2 – 07100 Sassari, Italy
2 Dipartimento di Scienze Chimiche e Geologiche,Cittadella Universitaria di Monserrato, 09042 Monserrato, Cagliari, Italy
Abstract: Guayule (Parthenium argentatum Gray) is a shrub native to the arid regions of Mexico. In the last decades, significant attention for its cultivation has risen because it is the raw material for the production of hypoallergenic natural rubber. Guayule biomass contains also high amounts of resin, which is normally not valorized in any way. Among other sesquiterpenic esters, resin contains also guayulins (i.e. the parteniol esters of cinnamic acid, guayulin A, or of anisic acid, guayulin B). In addition, minor amounts of guayulin C (4β-hydroxy-8α-p-cinnamoyloxy aromadendrene) and guayulin D (4β-hydroxy-8α-p-anisoyloxy aromadendrene) were formed from the esterification of a degradation product of parteniol with both cinnamic and anisic acids. Guayulins have been postulated to have a key role in the chemical defense system of Guayule and - for this reason – an application as natural insecticides seem to be feasible. In this contribution we propose an original and validated RP-HPLC approach to quantify guayulins A, B, C and D. Validation was accomplished in terms of limit of detection, limit of quantification, linearity, precision, and trueness. Finally, the method was tested with a number of real samples of Guayule from Mexico.