scholarly journals Non-chromatographic methods focused on speciation of arsenic and selenium in food and environmental samples

2015 ◽  
Vol 2 (1) ◽  
Author(s):  
Helen C. Rezende ◽  
Ione L. S. Almeida ◽  
Luciana M. Coelho ◽  
Nívia M. M. Coelho ◽  
Thiago L. Marques
Keyword(s):  
Sample Preparation ◽  
Environmental Samples ◽  
Final Analysis ◽  
Spectroscopic Techniques ◽  
Detection Techniques ◽  
Appropriate Treatment ◽  
Assisted Extraction ◽  
Recent Developments ◽  
And Storage

AbstractSpeciation is a promising and essential tool in the evaluation of the contamination of metals in food and environmental samples. In this context, information about the species of these elements is important considering that toxic effects are directly related to their chemical forms. The enormous progress in combining separation and detection techniques has enabled the effective chemical speciation. However, a possible source of error in studies of speciation occurs during sample preparation. Appropriate treatment of samples is necessary in order to ensure that interconversion between the species does not occur during the experimental procedure prior to the final analysis. In this review, methods of sample preparation for the determination of arsenic and selenium in food and environmental samples are discussed. We decided to focus on these elements since they account for around 50% of all speciation studies. Procedures including conventional extraction, microwave-assisted extraction and sonolysis are discussed as simple ways to ensure species selectivity. The main purpose of this review is to provide an update on the recent literature concerning the strategies for arsenic and selenium speciation and to critically discuss their advantages and weaknesses compared with the commonly accepted approach of combining non-chromatographic and spectroscopic techniques. The problems focused on involve sampling, sample preparation and storage, as well as changes in ‘species information’ that occur during the use of various separation technologies. These difficulties are described along with recent developments aimed at overcoming these potential issues.

scholarly journals Determination of trans fatty acids in foodstuffs by gas chromatography-mass spectrometry after simultaneous microwave-assisted extraction-esterification

2010 ◽  
Vol 75 (6) ◽  
pp. 803-812 ◽  
Author(s):  
Snezana Kravic ◽  
Zvonimir Suturovic ◽  
Jaroslava Svarc-Gajic ◽  
Zorica Stojanovic ◽  
Mira Pucarevic
Keyword(s):  
Mass Spectrometry ◽  
Sample Preparation ◽  
Preparation Method ◽  
Reference Method ◽  
Gas Chromatography Mass Spectrometry ◽  
Microwave Assisted Extraction ◽  
Sample Preparation Method ◽  
Microwave Assisted ◽  
Assisted Extraction

A sample preparation method based on the simultaneous microwave-assisted extraction-esterification (SMAEE) was developed for the determination of the fatty acid composition of foodstuffs by gas chromatography-mass spectrometry. The proposed sample preparation method was validated by comparison with the reference Soxhlet extraction method followed by derivatisation by ester formation and the same determination step. The fatty acid compositions and the extraction efficiencies obtained using the proposed SMAEE method and the reference method were statistically similar. The results showed that compared to the conventional method, the SMAEE method offered the advantages of short sample preparation time, low consumption of expensive organic solvents and lower energy consumption. This good agreement between results provided by both the SMAEE and the reference method demonstrates the usefulness of the former as a routine method for the treatment of food samples prior to trans fatty analysis.

scholarly journals DETERMINATION OF BTEX IN ENVIRONMENTAL SAMPLES: DEVELOPMENT AND PROTECTION OF TECHNOLOGIES AND ANALYTICAL METHODS

2019 ◽  
Vol 16 (31) ◽  
pp. 431-439
Author(s):  
Helilma de Andréa PINHEIRO ◽  
Ana Paula Mota FERREIRA ◽  
Ismael Carlos Braga ALVES ◽  
Antônio Fernandes SANTOS JÚNIOR ◽  
Raquel Bezerra dos Santos SAWCZUK ◽  
...  
Keyword(s):  
Petroleum Hydrocarbons ◽  
Environmental Samples ◽  
Low Cost ◽  
The United States ◽  
Operational Control ◽  
Toxic Compounds ◽  
Chromatographic Techniques ◽  
Benzene Toluene ◽  
And Storage

The contamination of water and soil by petroleum hydrocarbons is reported quite frequently, mainly due to accidents involving transport and storage of fuels. Among the most toxic compounds the most volatile benzene, toluene, ethylbenzene and xylene (BTEX). Residues of these compounds can cause serious environmental and public health troubles. Thus, more sensitive, selective and low-cost techniques, focused on the analysis and monitoring of these contaminants are being developed in order to establish operational control and to comply with local laws, but the intellectual property of such technologies is still unknown. The present study shows the panorama about patents, thesis and dissertations which have been already published on this theme. Together, the United States and China hold the largest number of patents, and most of thesis/dissertations describe methodologies for BTEX detection in water, although numerous environmental problems caused by oils in the soil had been reported. Also, the methods based on chromatographic techniques stand out in relation to the other techniques. It was possible to verify important advances in the field of sensors, especially the electrochemical ones, in order to solve the analytical gaps.

scholarly journals Determination of Surfactants in Environmental Samples. Part II. Anionic Compounds

2013 ◽  
Vol 20 (2) ◽  
pp. 331-342 ◽  
Author(s):  
Ewa Olkowska ◽  
Marek Ruman ◽  
Anna Kowalska ◽  
Żaneta Polkowska
Keyword(s):  
Environmental Samples ◽  
Anionic Surfactants ◽  
Solid Phase ◽  
Total Concentration ◽  
Polar Group ◽  
Surface Active Agents ◽  
Assisted Extraction ◽  
Surface Active ◽  
Living Organisms

Abstract Surface active agents (SAA) with negative charge of polar group are named as anionic compounds. They are the main constituent of most products containing synthetic surfactants. The linear alkylbenzene sulfonates (LAS), alkyl ethoxysulfates (AES) and alkyl sulfates (AS) are typically applied from this class of compounds. Those surfactants are ingredients of household detergents and cleaners, laundry detergents, cosmetic etc. Moreover they can be applied in the paper, textile and tanning industry as optical brighteners, dispersant, wetting and suspending agents. They can be substrates in the formulation of different products like dyes, pigments, pesticides, exchange resins, plasticizers and pharmaceuticals. Anionic surfactants after use are passed into sewage-treatment plants, where they are partially degraded and adsorbed to sewage sludge (applied in agriculture fields). Finally, the anionic SAA or their degradation products are discharged into surface waters and onto bottom sediments, soils or living organisms. Therefore, it is important (widely application, bioaccumulation, toxicity for living organisms) to investigate the environmental fate of those class of compounds in more details. This research involves determination the concentration of anionic surfactants with use appropriated analytical techniques in environmental samples The official methodology for determination of anionic SAA in liquid samples is based on the ion-pair reaction of these analytes compounds with methylene blue (MB) and an extraction with toxic solvent chloroform. During isolation step of anionic compounds from solid samples are employed Soxhlet and ultrasonic-assisted extraction techniques with use of methanol or mixture of other organic solvents as extraction medium. To overcome disadvantages of those traditional techniques were applied following techniques at sample preparation step from liquid and solid matrices: solid-phase extraction (SPE) and solid-phases microextraction (SPME); accelerated solvent extraction (ASE), microwave-assisted extraction (MAE), supercritical fluid extraction (SFE), respectively. For estimate total concentration of anionic analytes in extracts the spectrophotometric technique is used (as official regulation). For determination concentration of individual analytes were applied gas (derivatization step requires) and liquid chromatography mainly with mass spectrometry technique. The presence of anionic surface active agents was confirmed in various ecosystems (liquid and solid environmental samples).

scholarly journals Analytical Methodologies for the Determination of Endocrine Disrupting Compounds in Biological and Environmental Samples

2013 ◽  
Vol 2013 ◽  
pp. 1-23 ◽  
Author(s):  
Zoraida Sosa-Ferrera ◽  
Cristina Mahugo-Santana ◽  
José Juan Santana-Rodríguez
Keyword(s):  
Adverse Effects ◽  
Sample Preparation ◽  
Analytical Methods ◽  
Flame Retardants ◽  
Endocrine Disrupting Compounds ◽  
Synthetic Chemicals ◽  
Biological And Environmental Samples ◽  
Recent Developments ◽  
Natural Hormones

Endocrine-disruptor compounds (EDCs) can mimic natural hormones and produce adverse effects in the endocrine functions by interacting with estrogen receptors. EDCs include both natural and synthetic chemicals, such as hormones, personal care products, surfactants, and flame retardants, among others. EDCs are characterised by their ubiquitous presence at trace-level concentrations and their wide diversity. Since the discovery of the adverse effects of these pollutants on wildlife and human health, analytical methods have been developed for their qualitative and quantitative determination. In particular, mass-based analytical methods show excellent sensitivity and precision for their quantification. This paper reviews recently published analytical methodologies for the sample preparation and for the determination of these compounds in different environmental and biological matrices by liquid chromatography coupled with mass spectrometry. The various sample preparation techniques are compared and discussed. In addition, recent developments and advances in this field are presented.

scholarly journals A Fast Ultrasound-assisted Extraction Sample Preparation for Multi-elemental Determination of Contaminants in Pharmaceutical Ingredients by ICP-MS

2017 ◽  
Vol 38 (6) ◽  
pp. 165-173 ◽  
Author(s):  
Giovanna de Fatima Moreno Aguiar ◽  
Bruno Lemos Batista ◽  
Eloísa Silva de Paula ◽  
Andres Dobal Campíglia ◽  
Fernando Barbosa Jr.
Keyword(s):  
Sample Preparation ◽  
Ultrasound Assisted Extraction ◽  
Pharmaceutical Ingredients ◽  
Assisted Extraction ◽  
Icp Ms ◽  
Elemental Determination ◽  
Ultrasound Assisted

scholarly journals Seoul National University Accelerator Mass Spectrometry (SNU-AMS) Radiocarbon Date List IV

Radiocarbon ◽  
2007 ◽  
Vol 49 (3) ◽  
pp. 1395-1402 ◽  
Author(s):  
M Youn ◽  
Y M Song ◽  
J Kang ◽  
J C Kim ◽  
M K Cheoun
Keyword(s):  
Mass Spectrometry ◽  
Sample Preparation ◽  
Accelerator Mass Spectrometry ◽  
Environmental Samples ◽  
Before Present ◽  
Geological Data ◽  
National University ◽  
Recent Developments ◽  
Seoul National University ◽  
Accelerator System

The accelerator mass spectrometry (AMS) facility at Seoul National University (SNU-AMS) was accepted in December 1998 and results reported first at the Vienna AMS conference in October 1999 and at the 17th Radiocarbon Conference in Israel, June 2000. At the Vienna conference, we reported our accelerator system and sample preparation systems (Kim et al. 2000). Recent developments of the AMS facility have been regularly reported at AMS conferences (Kim et al. 2001, 2004, 2007). Meanwhile, about 1000 unknown archaeological, geological, and environmental samples have been measured every year. In this report, the archaeological and geological data carried out in 2002 are presented in terms of years BP (before present, AD 1950), following the SNU-AMS date lists I and II published in Radiocarbon (Kim et al. 2006a,b).

Methodological Aspects of Plant Sterol and Stanol Measurement

2015 ◽  
Vol 98 (3) ◽  
pp. 674-676 ◽  
Author(s):  
Dieter Lütjohann
Keyword(s):  
Sample Preparation ◽  
Biological Samples ◽  
Analytical Methods ◽  
Plant Sterol ◽  
Cholesterol Synthesis ◽  
Surrogate Markers ◽  
Lipid Research ◽  
Detection Techniques ◽  
Methodological Aspects

Abstract Cholesterol, its biosynthetic precursors, its metabolite 5α-cholestanol and plant sterols are widely used today in clinical lipid research as surrogate markers of cholesterol synthesis and absorption. Advances in analytical methods for the determination of serum noncholesterol sterols and stanols within the last century are highlighted. This review focuses on sample preparation, separation, and detection techniques. Various aspects related to sterol and stanol analysis from biological samples are discussed.

scholarly journals Sample Preparation Methods for Pesticides Analysis in Food Matrices and Environmental Samples by Chromatography-Based Techniques: A Review

2014 ◽  
Vol 5 (2) ◽  
Author(s):  
Elham Sobhanzadeh ◽  
Nor Kartini Abu Bakar ◽  
Mhd Radzi Abas ◽  
Keivan Nemati
Keyword(s):  
Sample Preparation ◽  
Pesticide Residues ◽  
Environmental Samples ◽  
Biological Fluids ◽  
Mass Spectrometric ◽  
Spectrometric Analysis ◽  
Pesticide Analysis ◽  
Preparation Methods ◽  
Sample Preparation Methods

Much attention has been made in pesticide analysis to improve agricultural productivity and control these compounds in food and environmental samples. Different methods have been applied in pesticide analysis, among these; methods based on chromatographic separation with mass spectrometric detection have been extremely useful methods for determination of pesticide residues. Despite employing of powerful instrumental techniques, the risk of interference increases with the complexity of the matrix studied, so sample preparation prior to instrumental analysis is necessary. This article reviews the analytical characteristics of the different sample preparation methods for determination of pesticide residues in food and environmental samples and biological fluids, moreover this study describes advantages, disadvantages and details on the analytical characteristics of the procedure that have been applied recently in different sample preparation methods and their application s in combination with chromatographic mass spectrometric analysis. This article provides selection of a reliable method which will be useful for the quantitative analysis of pesticide residues in variety of samples based on their evaluation in recent applications.

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