scholarly journals Microextraction Techniques as a Sample Preparation Step for Metal Analysis

10.5772/30501 ◽  
2012 ◽  
Author(s):  
Pourya Biparva ◽  
Amir Abbas
Keyword(s):  
Sample Preparation ◽  
Metal Analysis ◽  
Preparation Step ◽  
Microextraction Techniques

Recent Trends in the Development of Green Microextraction Techniques for the Determination of Hazardous Organic Compounds in Wine

2019 ◽  
Vol 15 (7) ◽  
pp. 788-800 ◽  
Author(s):  
Natasa P. Kalogiouri ◽  
Victoria F. Samanidou
Keyword(s):  
Sample Preparation ◽  
Solid Phase Extraction ◽  
Organic Compounds ◽  
Method Development ◽  
Solid Phase ◽  
Stir Bar Sorptive Extraction ◽  
Phase Extraction ◽  
Microextraction Techniques ◽  
Hazardous Organic Compounds

Background:The sample preparation is the most crucial step in the analytical method development. Taking this into account, it is easily understood why the domain of sample preparation prior to detection is rapidly developing. Following the modern trends towards the automation, miniaturization, simplification and minimization of organic solvents and sample volumes, green microextraction techniques witness rapid growth in the field of food quality and safety. In a globalized market, it is essential to face the consumers need and develop analytical methods that guarantee the quality of food products and beverages. The strive for the accurate determination of organic hazards in a famous and appreciated alcoholic beverage like wine has necessitated the development of microextraction techniques.Objective:The objective of this review is to summarize all the recent microextraction methodologies, including solid phase extraction (SPE), solid phase microextraction (SPME), liquid-phase microextraction (LPME), dispersive liquid-liquid microextraction (DLLME), stir bar sorptive extraction (SBSE), matrix solid-phase dispersion (MSPD), single-drop microextraction (SDME) and dispersive solid phase extraction (DSPE) that were developed for the determination of hazardous organic compounds (pesticides, mycotoxins, colorants, biogenic amines, off-flavors) in wine. The analytical performance of the techniques is evaluated and their advantages and limitations are discussed.Conclusion:An extensive investigation of these techniques remains vital through the development of novel strategies and the implication of new materials that could upgrade the selectivity for the extraction of target analytes.

Investigation of Phenolic Content in Five Different Pine Barks Species Grown in Turkey by HPLC-UV and LC–MS

2021 ◽  
Author(s):  
Mehmet Emin Şeker ◽  
Ali Çelik ◽  
Kenan Dost ◽  
Ayşegül Erdoğan
Keyword(s):  
Sample Preparation ◽  
Orthophosphoric Acid ◽  
Phenolic Content ◽  
Reversed Phase ◽  
Uv Detector ◽  
Epicatechin Gallate ◽  
Rp Hplc ◽  
Phenolic Constituents ◽  
Preparation Step ◽  
Very High

Abstract Investigation of phenolic content from different pine bark species grown in Turkey was performed using a reversed-phase high pressure liquid chromatography with ultraviolet (RP-HPLC-UV) method. All phenolic constituents were separated in <26 min on reversed-phase C18 column with gradient mobile phase that consists of orthophosphoric acid, methanol and acetonitrile. Detections were made on an UV detector at 280 nm and at a flow rate of 1 mL/min. Samples were prepared according to Masqueller’s conventional sample preparation method with slight modifications. To avoid the reduction in extraction efficiency the sample preparation step was carried out under argon atmosphere. The linearity of the method was between 0.9994 and 0.9999. The detection limits for the five phenolic constituents ranged from 0122 to 0.324 mg/L. Catechin and taxifolin were found in all pine barks at a concentration of 0.065 ± 0.002–1.454 ± 0.004 and 0.015 ± 0.001–23.164 ± 0.322 mg/g, respectively. Epicatechin was determined in four pine barks between 0.027 ± 0.001 and 0.076 ± 0.002 mg/g, ferulic acid in two pine barks between 0.010 ± 0.001 and 0.022 ± 0.001 mg/g and epicatechin gallate in only one of the pine barks at 0.025 ± 0.001 mg/g. Finally, the total amount of phenolic compounds and antioxidant capacities of the pine barks were found to be very high.

Optimization of Surface Properties for Nanoindentation Studies on Nuclear Structural Materials

2017 ◽  
Vol 891 ◽  
pp. 67-72
Author(s):  
Petra Bublíková ◽  
Hygreeva Kiran Namburi ◽  
Daniela Marušáková
Keyword(s):  
Mechanical Properties ◽  
Sample Preparation ◽  
Radiation Damage ◽  
High Sensitivity ◽  
Structural Materials ◽  
Thin Layers ◽  
Standard Methods ◽  
Electrolytic Polishing ◽  
Preparation Step ◽  
Extent Of Damage

Nanoindentation using static loading of indenter tip is one of versatile methods used for evaluation of materials in smaller volume. It includes investigation of structural phases and thin layers on substrates etc. In the field of nuclear core and structural materials, nanoindentation has become an important tool to assess mechanical properties and correlate to the level of radiation damage at elevated and room temperatures. Nanoindentation, ideally in combination with Transmission Electron Microscopy, can describe the extent of damage and behaviour from the nanoand micro scale. Due to the high sensitivity of nanoindentation system, that typically uses loads in the range of tens of nN up to several tens of mN, the precise sample preparation is challenging and to be performed especially to understand behaviour of bulk materials. In the current study, samples from Austenitic Stainless Steel (ASS) 321, which is the representative structural material used for reactor internals, were prepared by standard methods - fine polishing, chemical etching, electrolytic etching, electrolytic polishing, electrolytic polishing & etching and ion polishing. Firstly, non-irradiated samples were used for optimization of the sample preparation methodology and then it will be applied on irradiated samples to obtain local mechanical properties. After each preparation step, nanoindentation was performed and load was optimized leading to the minimum standard deviation, also taking into account an indent size and pile-up mechanism. Scanning Probe Microscopy (SPM imaging) and nanoindentation results showed the multi-grained austenitic structure with minimal roughness. Local mechanical properties can be measured according to the knowledge of radiation damage type and location, with focus on grain boundaries to be evaluated. This study shows that advanced methods such as ion polishing are not suitable for ASS preparation, but standard methods based on chemical reaction with structure, especially electrolytic polishing and etching, are highly recommended.

scholarly journals Alternative Green Extraction Phases Applied to Microextraction Techniques for Organic Compound Determination

Separations ◽  
2019 ◽  
Vol 6 (3) ◽  
pp. 35 ◽  
Author(s):  
Eduardo Carasek ◽  
Gabrieli Bernardi ◽  
Sângela N. do Carmo ◽  
Camila M.S. Vieira
Keyword(s):  
Organic Compound ◽  
Sample Preparation ◽  
Organic Compounds ◽  
Low Cost ◽  
Environmentally Friendly ◽  
New Materials ◽  
Green Extraction ◽  
Fields Of Study ◽  
Microextraction Techniques

The use of green extraction phases has gained much attention in different fields of study, including in sample preparation for the determination of organic compounds by chromatography techniques. Green extraction phases are considered as an alternative to conventional phases due to several advantages such as non-toxicity, biodegradability, low cost and ease of preparation. In addition, the use of greener extraction phases reinforces the environmentally-friendly features of microextraction techniques. Thus, this work presents a review about new materials that have been used in extraction phases applied to liquid and sorbent-based microextractions of organic compounds in different matrices.

scholarly journals New Advanced Materials and Sorbent-Based Microextraction Techniques as Strategies in Sample Preparation to Improve the Determination of Natural Toxins in Food Samples

Molecules ◽  
2020 ◽  
Vol 25 (3) ◽  
pp. 702 ◽  
Author(s):  
Natalia Casado ◽  
Judith Gañán ◽  
Sonia Morante-Zarcero ◽  
Isabel Sierra
Keyword(s):  
Sample Preparation ◽  
Food Samples ◽  
Advanced Materials ◽  
Preparation Methods ◽  
Matrix Interferences ◽  
Natural Toxins ◽  
Current Trends ◽  
Analytical Strategies ◽  
Microextraction Techniques ◽  
Exogenous Origin

Natural toxins are chemical substances that are not toxic to the organisms that produce them, but which can be a potential risk to human health when ingested through food. Thus, it is of high interest to develop advanced analytical methodologies to control the occurrence of these compounds in food products. However, the analysis of food samples is a challenging task because of the high complexity of these matrices, which hinders the extraction and detection of the analytes. Therefore, sample preparation is a crucial step in food analysis to achieve adequate isolation and/or preconcentration of analytes and provide suitable clean-up of matrix interferences prior to instrumental analysis. Current trends in sample preparation involve moving towards “greener” approaches by scaling down analytical operations, miniaturizing the instruments and integrating new advanced materials as sorbents. The combination of these new materials with sorbent-based microextraction technologies enables the development of high-throughput sample preparation methods, which improve conventional extraction and clean-up procedures. This review gives an overview of the most relevant analytical strategies employed for sorbent-based microextraction of natural toxins of exogenous origin from food, as well as the improvements achieved in food sample preparation by the integration of new advanced materials as sorbents in these microextraction techniques, giving some relevant examples from the last ten years. Challenges and expected future trends are also discussed.

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