scholarly journals Evaluation of Sample Preparation Strategies for Human Milk and Plasma Proteomics

Molecules ◽  
2021 ◽  
Vol 26 (22) ◽  
pp. 6816
Author(s):  
Sanja Milkovska-Stamenova ◽  
Michele Wölk ◽  
Ralf Hoffmann
Keyword(s):  
Sample Preparation ◽  
Human Milk ◽  
Biological Sample ◽  
Solid Phase ◽  
Protein Precipitation ◽  
Efficient Procedure ◽  
Identification Rate ◽  
Advantages And Disadvantages ◽  
Peak Areas ◽  
Proteins And Peptides

Sample preparation is the most critical step in proteomics as it directly affects the subset of proteins and peptides that can be reliably identified and quantified. Although a variety of efficient and reproducible sample preparation strategies have been developed, their applicability and efficacy depends much on the biological sample. Here, three approaches were evaluated for the human milk and plasma proteomes. Protein extracts were digested either in an ultrafiltration unit (filter-aided sample preparation, FASP) or in-solution (ISD). ISD samples were desalted by solid-phase extraction prior to nRPC-ESI-MS/MS. Additionally, milk and plasma samples were directly digested by FASP without prior protein precipitation. Each strategy provided inherent advantages and disadvantages for milk and plasma. FASP appeared to be the most time efficient procedure with a low miscleavage rate when used for a biological sample aliquot, but quantitation was less reproducible. A prior protein precipitation step improved the quantitation by FASP due to significantly higher peak areas for plasma and a much better reproducibility for milk. Moreover, the miscleavage rate for milk, the identification rate for plasma, and the carbamidomethylation efficiency were improved. In contrast, ISD of both milk and plasma resulted in higher miscleavage rates and is therefore less suitable for targeted proteomics.

scholarly journals THE METHOD OF PREPARING SOIL SAMPLES FOR SOIL – WATER CONTACT ANGLE MEASUREMENT USING SESSILE-DROP TECHNIQUE

2019 ◽  
pp. 91-112
Author(s):  
N. V. Matveeva ◽  
E. Yu. Milanovsky ◽  
O. B. Rogova
Keyword(s):  
Contact Angle ◽  
Sample Preparation ◽  
Sessile Drop ◽  
Solid Phase ◽  
Chestnut Soil ◽  
Soil Samples ◽  
Adhesive Tape ◽  
Membrane Filters ◽  
Advantages And Disadvantages ◽  
Significant Difference

The method of soil samples preparation for measuring the (wetting) contact angle (CA) of the soil solid phase surface using membrane filters is proposed. The samples of kaolinite, a standard sample of chernozem and samples of agro-chestnut soil were taken for the experiment. The results of the CA measurements using two types of sample preparation for the analysis were compared. The first method of sample preparation was to apply a sample to a double-sided adhesive tape; the second method involved the deposition of suspensions of the studied samples of certain concentrations on membrane filters. The advantages and disadvantages of each sample preparation method are described. The significant difference in the obtained CA values depending on the sample preparation for measurement was revealed. The method of sample preparation with the use of membrane filters developed by the authors made it possible to reduce the CA measurement error by more than 2 times. Reducing the variation of the CA value of a single sample will allow comparing similar soil samples, including soils of the same type, but involved in different land use systems.

scholarly journals Recent Trends in Solid-Phase Extraction for Environmental, Food and Biological Sample Preparation

2019 ◽  
Vol 82 (8) ◽  
pp. 1119-1120 ◽  
Author(s):  
Anna Laura Capriotti ◽  
Giorgia La Barbera ◽  
Susy Piovesana
Keyword(s):  
Sample Preparation ◽  
Solid Phase Extraction ◽  
Biological Sample ◽  
Solid Phase ◽  
Phase Extraction ◽  
Recent Trends

scholarly journals Restricted Access Molecularly Imprinted Polymers for Biological Sample Preparation

2021 ◽  
Vol 9 (35) ◽  
Author(s):  
Tássia Mendes ◽  
Mariana Rosa ◽  
Eduardo Figueiredo
Keyword(s):  
Sample Preparation ◽  
Molecularly Imprinted Polymers ◽  
Biological Sample ◽  
Organic Molecules ◽  
Solid Phase ◽  
Molecularly Imprinted ◽  
Restricted Access ◽  
Small Organic Molecules ◽  
Imprinted Polymers ◽  
Hydrophilic Monomer

Restricted access molecularly imprinted polymers (RAMIPs) have been efficiently used for the extraction of small organic molecules from untreated biological matrices (e.g. blood, plasma, serum, and milk). These materials have been obtained by modifying the external surface of conventional molecularly imprinted polymers (MIPs) with hydrophilic monomer grafting, crosslinked protein capsule or a combination of both. These sorbents aggregate the selectivity of MIPs with the ability to exclude macromolecules of restricted access materials (RAMs), being widely employed in solid phase extraction techniques, beyond their use in sensors. In this review, we discuss about the design and application of RAMIPs in biological sample preparation, emphasizing the future trends and remaining challenges of this technology for bioanalyses.

scholarly journals Extended characterization of petroleum aromatics using off-line LC-GC-MS

2021 ◽  
Vol 3 ◽  
pp. e12
Author(s):  
Khoa Huynh ◽  
Annette E. Jensen ◽  
Jonas Sundberg
Keyword(s):  
High Resolution ◽  
Sample Preparation ◽  
Solid Phase Extraction ◽  
Crude Oil ◽  
High Resolution Mass Spectrometry ◽  
Solid Phase ◽  
Chemical Space ◽  
Phase Extraction ◽  
Advantages And Disadvantages

Characterization of crude oil remains a challenge for analytical chemists. With the development of multi-dimensional chromatography and high-resolution mass spectrometry, an impressive number of compounds can be identified in a single sample. However, the large diversity in structure and abundance makes it difficult to obtain full compound coverage. Sample preparation methods such as solid-phase extraction and SARA-type separations are used to fractionate oil into compound classes. However, the molecular diversity within each fraction is still highly complex. Thus, in the routine analysis, only a small part of the chemical space is typically characterized. Obtaining a more detailed composition of crude oil is important for production, processing and environmental aspects. We have developed a high-resolution fractionation method for isolation and preconcentration of trace aromatics, including oxygenated and nitrogen-containing species. The method is based on semi-preparative liquid chromatography. This yields high selectivity and efficiency with separation based on aromaticity, ring size and connectivity. By the separation of the more abundant aromatics, i.e., monoaromatics and naphthalenes, trace species were isolated and enriched. This enabled the identification of features not detectable by routine methods. We demonstrate the applicability by fractionation and subsequent GC-MS analysis of 14 crude oils sourced from the North Sea. The number of tentatively identified compounds increased by approximately 60 to 150% compared to solid-phase extraction and GC × GC-MS. Furthermore, the method was used to successfully identify an extended set of heteroatom-containing aromatics (e.g., amines, ketones). The method is not intended to replace traditional sample preparation techniques or multi-dimensional chromatography but acts as a complementary tool. An in-depth comparison to routine characterization techniques is presented concerning advantages and disadvantages.

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.

scholarly journals A Toolbox for the Determination of Nitroaromatic Explosives in Marine Water, Sediment, and Biota Samples on Femtogram Levels by GC-MS/MS

Toxics ◽  
2021 ◽  
Vol 9 (3) ◽  
pp. 60
Author(s):  
Tobias Hartwig Bünning ◽  
Jennifer Susanne Strehse ◽  
Ann Christin Hollmann ◽  
Tom Bötticher ◽  
Edmund Maser
Keyword(s):  
Sample Preparation ◽  
Freeze Drying ◽  
Solid Phase ◽  
Phase Extraction ◽  
Direct Extraction ◽  
Time Saving ◽  
Marine Samples ◽  
Volume Method ◽  
Biota Samples

To determine the amount of the explosives 1,3-dinitrobenzene, 2,4-dinitrotoluene, 2,4,6-trinitrotoluene, and its metabolites in marine samples, a toolbox of methods was developed to enhance sample preparation and analysis of various types of marine samples, such as water, sediment, and different kinds of biota. To achieve this, established methods were adapted, improved, and combined. As a result, if explosive concentrations in sediment or mussel samples are greater than 10 ng per g, direct extraction allows for time-saving sample preparation; if concentrations are below 10 ng per g, techniques such as freeze-drying, ultrasonic, and solid-phase extraction can help to detect even picogram amounts. Two different GC-MS/MS methods were developed to enable the detection of these explosives in femtogram per microliter. With a splitless injector, limits of detection (LODs) between 77 and 333 fg/µL could be achieved in only 6.25 min. With the 5 µL programmable temperature vaporization—large volume method (PTV-LVI), LODs between 8 and 47 fg/µL could be achieved in less than 7 min. The detection limits achieved by these methods are among the lowest published to date. Their reliability has been tested and confirmed by measuring large and diverse sample sets.

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