scholarly journals DEVELOPMENT AND VALIDATION OF UV-VISIBLE SPECTROPHOTOMETRIC METHOD FOR ANALYSIS OF BOSENTAN IN SPIKED HUMAN PLASMA

2019 ◽  
pp. 108-110
Author(s):  
BHAVYA SRI K. ◽  
MOUNIKA C. H.
Keyword(s):  
Sample Preparation ◽  
Human Plasma ◽  
Spectrophotometric Method ◽  
Preparation Method ◽  
Analytical Techniques ◽  
Sample Preparation Method ◽  
Spiked Human Plasma ◽  
Analytical Technique ◽  
Uv Visible ◽  
Development And Validation

Objective: The aim of the present study is to develop and validate a simple, efficient, economical and accurate UV-visible spectrophotometric method for estimation of bosentan in spiked human plasma. Methods: The analyte was extracted by Liquid-liquid Extraction (LLE) procedure using acetonitrile and chloroform. Absorbance of the analyte in the extract was measured at 270 nm using ethanol as a diluent. The developed method was validated for linearity, accuracy and robustness. Results: The proposed method was found to be linear in the range of 6 to 18 mg/ml. The correlation coefficient (r2) was found to be 0.99. The results revealed that the linearity, accuracy and robustness of the developed method were within the acceptable range. Conclusion: The analytical technique presented here demonstrates shorter and easier sample preparation method, decreased analysis time and reduces the need for complicated or expensive equipment. The sample preparation method used in this study can also be further extended to higherend analytical techniques and other biological samples for quantification of bosentan.

scholarly journals Immunoradiometric quantitation of tissue plasminogen activator-related antigen in human plasma: crypticity phenomenon and relationship to plasma fibrinolysis

Blood ◽  
1987 ◽  
Vol 69 (5) ◽  
pp. 1348-1353 ◽  
Author(s):  
TC Wun ◽  
A Capuano
Keyword(s):  
Sample Preparation ◽  
Human Plasma ◽  
Plasminogen Activator ◽  
Tissue Plasminogen Activator ◽  
Preparation Method ◽  
Blood Bank ◽  
Immunoradiometric Assay ◽  
Plasma Samples ◽  
Sample Preparation Method ◽  
Tissue Plasminogen

Abstract A two-site immunoradiometric assay for tissue plasminogen activator (tPA) antigen has been developed using immunoaffinity purified antibody. Various treatments enhanced the detection of tPA antigen in the plasma samples. Maximum detection was obtained by acidification of plasma to pH 4.8 to 6.5 or addition of 0.5 mol/L of L-lysine or L- arginine. Acidification or addition of lysine to plasma is also required for maximum immunoadsorption of plasma tPA antigen on anti-tPA- Ig-sepharose. These results indicate that plasma tPA antigen is partially cryptic to antibody in untreated plasma. The plasma tPA antigen isolated by immunoadsorption of either untreated plasma or acidified plasma on anti-tPA-Ig-sepharose consists mainly of a 100-kd plasminogen activator species as determined by fibrin-agar zymography. The 100-kd activity is possibly a tPA:inhibitor complex. A standardized sample preparation method was conveniently adopted by mixing 3 vol of plasma and 1 vol of 2 mol/L of L-lysine for the assay. Reconstitution and recovery studies showed that the method is specific and permits full detection of both free tPA and tPA:inhibitor complex. The validity of the assay is further supported by the finding that the spontaneous plasma fibrinolysis previously demonstrated to be dependent on plasma tPA antigen is correlated with tPA antigen content. Using the standardized assay, we found that tPA antigen concentrations in 16 blood bank plasmas are equivalent to 3.7 to 20 ng of 60 kd tPA/mL. In all the plasma tested, more than half of the antigen is undetected unless the plasma is treated as described above.

scholarly journals Immunoradiometric quantitation of tissue plasminogen activator-related antigen in human plasma: crypticity phenomenon and relationship to plasma fibrinolysis

Blood ◽  
1987 ◽  
Vol 69 (5) ◽  
pp. 1348-1353
Author(s):  
TC Wun ◽  
A Capuano
Keyword(s):  
Sample Preparation ◽  
Human Plasma ◽  
Plasminogen Activator ◽  
Tissue Plasminogen Activator ◽  
Preparation Method ◽  
Blood Bank ◽  
Immunoradiometric Assay ◽  
Plasma Samples ◽  
Sample Preparation Method ◽  
Tissue Plasminogen

A two-site immunoradiometric assay for tissue plasminogen activator (tPA) antigen has been developed using immunoaffinity purified antibody. Various treatments enhanced the detection of tPA antigen in the plasma samples. Maximum detection was obtained by acidification of plasma to pH 4.8 to 6.5 or addition of 0.5 mol/L of L-lysine or L- arginine. Acidification or addition of lysine to plasma is also required for maximum immunoadsorption of plasma tPA antigen on anti-tPA- Ig-sepharose. These results indicate that plasma tPA antigen is partially cryptic to antibody in untreated plasma. The plasma tPA antigen isolated by immunoadsorption of either untreated plasma or acidified plasma on anti-tPA-Ig-sepharose consists mainly of a 100-kd plasminogen activator species as determined by fibrin-agar zymography. The 100-kd activity is possibly a tPA:inhibitor complex. A standardized sample preparation method was conveniently adopted by mixing 3 vol of plasma and 1 vol of 2 mol/L of L-lysine for the assay. Reconstitution and recovery studies showed that the method is specific and permits full detection of both free tPA and tPA:inhibitor complex. The validity of the assay is further supported by the finding that the spontaneous plasma fibrinolysis previously demonstrated to be dependent on plasma tPA antigen is correlated with tPA antigen content. Using the standardized assay, we found that tPA antigen concentrations in 16 blood bank plasmas are equivalent to 3.7 to 20 ng of 60 kd tPA/mL. In all the plasma tested, more than half of the antigen is undetected unless the plasma is treated as described above.

scholarly journals Sample Preparation Strategies for Antibody-Free Quantitative Analysis of High Mobility Group Box 1 Protein

2021 ◽  
Vol 14 (6) ◽  
pp. 537
Author(s):  
Ingeborg Kvivik ◽  
Grete Jonsson ◽  
Roald Omdal ◽  
Cato Brede
Keyword(s):  
Liquid Chromatography ◽  
Sample Preparation ◽  
Human Plasma ◽  
Preparation Method ◽  
High Mobility ◽  
Reversed Phase ◽  
High Mobility Group ◽  
Detection Sensitivity ◽  
Sample Preparation Method ◽  
Free Sample

Sickness behavior and fatigue are induced by cerebral mechanisms involving inflammatory cytokines. High mobility group box 1 (HMGB1) is an alarmin, and a potential key player in this process. Reliable quantification methods for total HMGB1 and its redox variants must be established in order to clearly understand how it functions. Current methods pose significant challenges due to interference from other plasma proteins and autoantibodies. We aimed to develop an antibody-free sample preparation method followed by liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) to measure HMGB1 in human plasma. Different methods were applied for the removal of interfering proteins and the enrichment of HMGB1 from spiked human plasma samples. A comparison of methods showed an overall low extraction recovery (<40%), probably due to the stickiness of HMGB1. Reversed-phase liquid chromatography separation of intact proteins in diluted plasma yielded the most promising results. The method produced an even higher degree of HMGB1 purification than that observed with immunoaffinity extraction. Detection sensitivity needs to be further improved for the measurement of HMGB1 in patient samples. Nevertheless, it has been demonstrated that a versatile and fully antibody-free sample preparation method is possible, which could be of great use in further investigations.

To Eliminate Curtain Effect of FIB TEM Samples by a Combination of Sample Dicing and Backside Milling

2014 ◽  
Author(s):  
Jian-Shing Luo ◽  
Hsiu Ting Lee
Keyword(s):  
Sample Preparation ◽  
Focused Ion Beam ◽  
Preparation Method ◽  
Low Cost ◽  
Ion Beam ◽  
Sample Preparation Method ◽  
Site Specific ◽  
Dual Beam ◽  
Transmission Electron

Abstract Several methods are used to invert samples 180 deg in a dual beam focused ion beam (FIB) system for backside milling by a specific in-situ lift out system or stages. However, most of those methods occupied too much time on FIB systems or requires a specific in-situ lift out system. This paper provides a novel transmission electron microscopy (TEM) sample preparation method to eliminate the curtain effect completely by a combination of backside milling and sample dicing with low cost and less FIB time. The procedures of the TEM pre-thinned sample preparation method using a combination of sample dicing and backside milling are described step by step. From the analysis results, the method has applied successfully to eliminate the curtain effect of dual beam FIB TEM samples for both random and site specific addresses.

Cross-Section Sample Preparation Method for Imaging Dopant Related Anomalies Using Scanning Probe Microscopy Techniques

2014 ◽  
Author(s):  
Swaminathan Subramanian ◽  
Khiem Ly ◽  
Tony Chrastecky
Keyword(s):  
Sample Preparation ◽  
Failure Analysis ◽  
Cross Section ◽  
Scanning Probe Microscopy ◽  
Preparation Method ◽  
Fault Isolation ◽  
Scanning Probe ◽  
Sample Preparation Method ◽  
Probe Microscopy ◽  
Section Sample

Abstract Visualization of dopant related anomalies in integrated circuits is extremely challenging. Cleaving of the die may not be possible in practical failure analysis situations that require extensive electrical fault isolation, where the failing die can be submitted of scanning probe microscopy analysis in various states such as partially depackaged die, backside thinned die, and so on. In advanced technologies, the circuit orientation in the wafer may not align with preferred crystallographic direction for cleaving the silicon or other substrates. In order to overcome these issues, a focused ion beam lift-out based approach for site-specific cross-section sample preparation is developed in this work. A directional mechanical polishing procedure to produce smooth damage-free surface for junction profiling is also implemented. Two failure analysis applications of the sample preparation method to visualize junction anomalies using scanning microwave microscopy are also discussed.

Recent Developments in CE-MS Based Metabolomics

2020 ◽  
Vol 16 ◽  
Author(s):  
Mustafa Çelebier ◽  
Merve Nenni
Keyword(s):  
Sample Preparation ◽  
Scientific Information ◽  
Analytical Techniques ◽  
Living Organism ◽  
Analytical Technique ◽  
Ionic Compounds ◽  
Recent Sample ◽  
Recent Developments ◽  
Endogenous Metabolites ◽  
Preparation Techniques

Background: Metabolomics has gained importance in clinical applications over the last decade. Metabolomics studies are significant because the systemic metabolome is directly affected by disease conditions. Metabolome-based biomarkers are actively being developed for early diagnosis and to indicate the stage of specific diseases. Additionally, understanding the effect of an intervention on a living organism at the molecular level is a crucial strategy for understanding novel or unexpected biological processes. Results: The simultaneous improvements in advanced analytical techniques, sample preparation techniques, computer technology, and databank contents has enabled more valuable scientific information to be gained from metabolomics than ever before. With over 15,000 known endogenous metabolites, there is no single analytical technique capable of analyzing the whole metabolome. However, capillary electrophoresis-mass spectrometry (CE-MS) is a unique technique used to analyze an important portion of metabolites not accessible by liquid chromatography or gas chromatography techniques. The analytical capability of CE, combined with recent sample preparation techniques focused on extracting polar-ionic compounds, make CE-MS a perfect technique for metabolomic studies. Conclusion: Here, previous reviews of CE-MS based metabolomics are evaluated to highlight recent improvements in this technique. Specifically, we review papers from the last two years (2018 and 2019) on CE-MS based metabolomics. The current situation and the challenges facing metabolomic studies are discussed to reveal the high potential of CE-MS for further studies, especially in biomarker development studies.

scholarly journals Application of the Dehydration Homogeneous Liquid–Liquid Extraction (DHLLE) Sample Preparation Method for Fingerprinting of Honey Volatiles

Molecules ◽  
2021 ◽  
Vol 26 (8) ◽  
pp. 2277
Author(s):  
Piotr M. Kuś ◽  
Igor Jerković
Keyword(s):  
Carboxylic Acid ◽  
Sample Preparation ◽  
Preparation Method ◽  
Liquid Extraction ◽  
Sample Preparation Method ◽  
Phenyllactic Acid ◽  
Homogeneous Liquid ◽  
Liquid Liquid Extraction ◽  
Wide Range ◽  
Chemical Groups

Recently, we proposed a new sample preparation method involving reduced solvent and sample usage, based on dehydration homogeneous liquid–liquid extraction (DHLLE) for the screening of volatiles and semi-volatiles from honey. In the present research, the method was applied to a wide range of honeys (21 different representative unifloral samples) to determine its suitability for detecting characteristic honey compounds from different chemical classes. GC-FID/MS disclosed 130 compounds from different structural and chemical groups. The DHLLE method allowed the extraction and identification of a wide range of previously reported specific and nonspecific marker compounds belonging to different chemical groups (including monoterpenes, norisoprenoids, benzene derivatives, or nitrogen compounds). For example, DHLLE allowed the detection of cornflower honey chemical markers: 3-oxo-retro-α-ionols, 3,4-dihydro-3-oxoedulan, phenyllactic acid; coffee honey markers: theobromine and caffeine; linden honey markers: 4-isopropenylcyclohexa-1,3-diene-1-carboxylic acid and 4-(2-hydroxy-2-propanyl)cyclohexa-1,3-diene-1-carboxylic acid, as well as furan derivatives from buckwheat honey. The obtained results were comparable with the previously reported data on markers of various honey varieties. Considering the application of much lower volumes of very common reagents, DHLLE may provide economical and ecological advantages as an alternative sample preparation method for routine purposes.

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