Tea is the second most consumed beverage in the world and its consumption has been associated with numerous potential health benefits. Factors such as fermentation methods, geographical origin and season can affect the primary and secondary metabolite composition of tea. In this study, a hydrophilic interaction liquid chromatography (HILIC) method coupled to high resolution mass spectrometry in both positive and negative ionisation modes was developed and optimised. The method when combined with principal component analysis to analyse three different types of tea, successfully distinguished samples into different categories, and provided evidence of the metabolites which differed between them. The accurate mass and high resolution attributes of the mass spectrometric data were utilised and relative quantification data were extracted post-data acquisition on 18 amino acids, showing significant differences in amino acid concentrations between tea types and countries. This study highlights the ...

A method for the analysis of dextran-1 has been developed using hydrophilic interaction liquid chromatography (HILIC) with charged corona aerosol detection (CCAD) as a potential alternative to the size exclusion chromatography method described in the European Pharmacopoeia (EP). Click to read more...

Title: Stable isotope dilution liquid chromatography/mass spectrometry analysis of cellular and tissue medium- and long-chain acyl-coenzyme A thioesters.. Authors: Snyder, Nathaniel W; Basu, Sankha S; Zhou, Zinan; Worth, Andrew J; Blair, Ian A. Published In Rapid Commun Mass Spectrom, (2014 Aug 30). Abstract: Acyl-Coenzyme A (CoA) thioesters are the principal form of activated carboxylates in cells and tissues. They are employed as acyl carriers that facilitate the transfer of acyl groups to lipids and proteins. Quantification of medium- and long-chain acyl-CoAs represents a significant bioanalytical challenge because of their instability.Stable isotope dilution liquid chromatography/selected reaction monitoring-mass spectrometry (LC/SRM-MS) provides the most specific and sensitive method for the analysis of CoA species. However, relevant heavy isotope standards are not available and they are challenging to prepare by chemical synthesis. Stable isotope labeling by essential nutrients in cell ...

Differential mobility spectrometry for improved selectivity in hydrophilic interaction liquid chromatography-tandem mass spectrometry analysis of paralytic shellfish toxins

article{167611, author = {Van de Wiele, Mieke and De Wasch, Katia and VERCAMMEN, J and COURTHEYN, D and De Brabander, Hubert and Impens, Sandra}, issn = {0021-9673}, journal = {JOURNAL OF CHROMATOGRAPHY A}, language = {eng}, number = {2}, pages = {203--209}, title = {Determination of 16 beta-hydroxystanozolol in urine and faeces by liquid chromatography-multiple mass spectrometry.}, volume = {904}, year = {2000 ...

Close The Infona portal uses cookies, i.e. strings of text saved by a browser on the users device. The portal can access those files and use them to remember the users data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser. ...

Simultaneous determination of β-hydroxybutyrate and β-hydroxy-β-methylbutyrate in human whole blood using hydrophilic interaction liquid chromatography electrospray tandem mass ...

A free platform for explaining your research in plain language, and managing how you communicate around it - so you can understand how best to increase its impact.

A recently developed stable isotope dilution liquid chromatography-multiple reaction/mass spectrometry method to quantify focal adhesion kinase (FAK) activation loop phosphorylation was used to study endogenous Src kinase activity. This revealed that bis-phosphorylated pTyr576/Tyr577-FAK was a biomarker of Src activity and inactivation in vitro and in cell culture. Mouse embryonic fibroblasts (MEFs) expressing endogenous Src family kinases contained 65% unmodified Tyr576/Tyr577, 33% mono-phosphorylated-pTyr576-FAK, and 6% bis-phosphorylated-pTyr576/pTyr577-FAK. In contrast, MEFs expressing oncogenic Y529FSrc contained 38% unmodified Tyr576/Tyr577-FAK, 29% mono-phosphorylated-pTyr576-FAK, and 19% bis-phosphorylated-pTyr576/pTyr577-FAK. This new method has made it possible to accurately determine the absolute amounts of FAK phosphorylation that occur after Src inhibition in cell culture and in vitro with increasing concentrations of the Src inhibitor ...

To better understand the molecular mechanisms underpinning physiological variation in human populations, metabolic phenotyping approaches are increasingly being applied to studies involving hundreds and thousands of biofluid samples. Hyphenated ultra-performance liquid chromatography-mass spectrometry (UPLC-MS) has become a fundamental tool for this purpose. However, the seemingly inevitable need to analyze large studies in multiple analytical batches for UPLC-MS analysis poses a challenge to data quality which has been recognized in the field. Herein, we describe in detail a fit-for-purpose UPLC-MS platform, method set, and sample analysis workflow, capable of sustained analysis on an industrial scale and allowing batch-free operation for large studies. Using complementary reversed-phase chromatography (RPC) and hydrophilic interaction liquid chromatography (HILIC) together with high resolution orthogonal acceleration time-of-flight mass spectrometry (oaTOF-MS), exceptional measurement precision is

Mitochondrial dysfunction plays a role in a wide range of diseases resulting in an enormous public health burden. The goal of this thesis is to identify metabolic pathways that are disrupted in response to mitochondrial insults. A large proportion of this work is based on the generation of stable isotope labelled metabolites to allow for the rigorous quantification of intracellular metabolites by liquid chromatography-mass spectrometry. Once developed, this methodology was employed in cell culture models initially to characterize an unidentified acyl-CoA thioester induced by propionate metabolism. This novel pathway was identified as the direct formation of 2-methyl-2-pentenoyl-CoA, and using isotopic labeling by metabolic precursors served as a critical component to this pathway elucidation. These same techniques were then applied to studying rotenone, a mitochondrial complex I inhibitor associated with Parkinsonâ??s disease. Previous work by our group has shown that rotenone inhibits components of

PubMed Central Canada (PMC Canada) provides free access to a stable and permanent online digital archive of full-text, peer-reviewed health and life sciences research publications. It builds on PubMed Central (PMC), the U.S. National Institutes of Health (NIH) free digital archive of biomedical and life sciences journal literature and is a member of the broader PMC International (PMCI) network of e-repositories.

Quantification of highly homologous human liver drug-metabolizing enzymes (DMEs) has been a challenging task in drug metabolism and disposition research, due to a lack of specific antibodies and marker substrates. Mass spectrometry (MS) techniques and applications have evolved significantly, striving to achieve absolute and specific quantification of these enzymes. Since the first absolute quantification of cytochrome P450s (CYPs) using the attachment of isotope tags to free thiols (iCAT), MS-based quantification has become much more versatile, cheaper, and easier to use. Today, variations of liquid chromatography-multiple reaction monitoring (LC-MRM)-based targeted proteomics, such as AQUA (absolute quantification) and QconCAT (concatenated signature peptides), have become the gold standards for quantification. These new methods have driven the absolute quantification of DMEs to become a routine laboratory task. Many drug metabolism-related projects require absolute enzyme quantification. For ...

In a preliminary study in healthy subjects, the investigators determined the pharmacokinetic and pharmacodynamic of enteric-coated acetylsalicylic acid (ASA) (Adiro 100 mg, Bayer), and the variability (coefficient of variation), accuracy and precision of a novel biomarker of ASA action, i.e., quantification of the extent of COX-1 acetylation at serine-529, using a stable isotope dilution liquid chromatography multiple reaction monitoring/mass spectrometry (LC-MS) technique.. Now, the investigators will perform a clinical study in individuals undergoing Colorectal cancer (CRC) to validate the hypothesis that that low-dose ASA given once daily is acting primarily by selectively acetylating platelet COX-1 and suppressing its activity throughout the 24-hour dosing interval. In contrast, it is expected that the inhibitory effect on extra-platelet sources of COX-1 will be short-lasting, if any, affecting only partially COX-1, and this effect will be completely reversed at 24 hours after dosing. This ...

A novel bioanalytical method was developed and validated for the quantitative determination of erlotinib in human plasma by using the supported liquid extraction (SLE) sample cleanup coupled with hydrophilic interaction liquid chromatography and tandem mass spectrometric detection (HILIC-MS/MS). The SLE extract could be directly injected into the HILIC-MS/MS system for analysis without the solvent evaporation and reconstitution steps. Therefore, the method is simple and rapid. In the present method, erlotinib-d6 was used as the internal standard. The SLE extraction recovery was 101.3%. The validated linear curve range was 2 to 2,000 ng/mL based on a sample volume of 0.100-mL, with a linear correlation coefficient of | 0.999. The validation results demonstrated that the present method gave a satisfactory precision and accuracy: intra-day CV | 5.9% (

Protein recovery is crucial for shotgun metaproteomics to study the in situ functionality of microbial populations from complex biofilms but still poorly addressed by far. To fill this knowledge gap, we systematically evaluated the sample preparation with extraction buffers comprising four detergents for the metaproteomics analysis of a terephthalate-degrading methanogenic biofilm using an on-line two-dimensional liquid chromatography tandem mass spectrometry (2D-LC-MS/MS) system. Totally, 1018 non-repeated proteins were identified with the four treatments. On the whole, each treatment could recover the biofilm proteins with specific distributions of molecular weight, hydrophobicity, and isoelectric point. The extraction buffers containing zwitterionic and anionic detergents were found to harvest the proteins with better efficiency and quality, allowing identification up to 76.2% of total identified proteins with the LC-MS/MS analysis. According to the annotation with a relevant metagenomic

Biosero provide liquid chromatography & mass spectrometry software. The LC/MS method is useful because it can analyze large volumes of material with specificity and sensitivity.

Biosero provide liquid chromatography & mass spectrometry software. The LC/MS method is useful because it can analyze large volumes of material with specificity and sensitivity.

Table IV shows that 91% of the 229 proteins reported by Mascot are correct. This slight discrepancy between the predicted performance of Mascot and that reported can be explained by the confusion/difficulty in defining a correct answer. Eight of the 20 proteins that we have defined as incorrect for Mascot are proteins that are homologous to proteins that are present in the sample (i.e. some of the peptide matches to this protein are correct, but the unique peptide matches to this protein are incorrect). Although these matches are not correct, they do share extensive homology to correct matches. Adding these matches leads to the Mascot scoring performing as its scoring model predicts (94.8% correct).. Protein Prospector searching against the Swiss-Prot database and using a 0.5 peptide match probability threshold for reporting proteins returns 256 protein matches plus a further 57 homologous proteins. Protein Prospector tries to separate homologous proteins out of the main protein list, so ...

New Liquid Chromatography-Mass Spectrometry Workstream Offers Comprehensive Solution for Toxicology - read this article along with other careers information, tips and advice on BioSpace

Lin XH,WangQuancai,Yin PY,et al. A method for handling metabonomics data from liquid chromatography mass spectrometry: combinational use of support vector machine recursive feature elimination, genetic algorithm and random forest for feature selection[J]. Metabolomics,2011,4(待补充):549 ...

Agilent Technologies Inc. announced analyses of carbamates and phenyl ureas using liquid chromatography/mass spectrometry (LC/MS). The sources for these tes

The capability to separate and analyze a wide range of proteins in complex systems remains a prime requirement in the biochemical sciences. Intact protein separations are especially difficult as these large molecules can present different conformations, association states and amphoteric features with chromatographic surfaces. Combining high performance liquid chromatography (HPLC) and ultrahigh pressure liquid chromatography (UHPLC) with mass spectrometry (MS) has proven to be an effective approach for solving difficult problems involving protein analyses. Considerable effort has been made to develop columns for separating proteins with high efficiency for reversed-phase, ion-exchange, size-exclusion chromatography, hydrophilic interaction liquid chromatography (HILIC), and hydrophobic interaction chromatography (HIC). Even so, many situations still exist where insufficient resolution is available for accurate protein analysis even when high-resolution MS is available. This presentation provides ...

New high sensitivity analytical instrument at NIOM February 27th 2017. - NIOM has recently acquired a high sensitivity ultra-high performance liquid chromatography mass spectrometry (UHPLC-MS) instrument.. ...

Robust statistical inference for quantitative LC-MS proteomics - GitHub - statOmics/MSqRob: Robust statistical inference for quantitative LC-MS proteomics

Interest in chromatography using hydrophilic interaction liquid chromatography (HILIC) has continued to build in recent years. Although HILIC chromatography is known to provide valuable retention and selectivity of polar compounds and provide highly compa...

Currently, statins are the only drugs acting on the mammalian isoprenoid pathway. The mammalian genes in this pathway are not easily amenable to genetic manipulation. Thus, it is difficult to study the effects of the inhibition of various enzymes on the intermediate and final products in the isoprenoid pathway. In fission yeast, antifungal compounds such as azoles and terbinafine are available as inhibitors of the pathway in addition to statins, and various isoprenoid pathway mutants are also available. Here in these mutants, treated with statins or antifungals, we quantified the final and intermediate products of the fission yeast isoprenoid pathway using liquid chromatography-mass spectrometry/mass spectrometry. In hmg1-1, a mutant of the gene encoding 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMGR), ergosterol (a final sterol product), and squalene (an intermediate pathway product), were decreased to approximately 80% and 10%, respectively, compared with that of wild-type cells. Consistently

[163 Pages] Global liquid chromatography-mass spectrometry market is expected to be valued at US$ 3,683.7 million in 2019. Liquid Chromatography-Mass Spectrometry Market by Type, by Sensitivity, by End User, and Regional Outlook 2019 - 2027

Methylation aberrations play an important role in many metabolic disorders including cancer. Methylated metabolites are direct indicators of metabolic aberrations, and currently, there is no liquid chromatography-mass spectrometry (LC-MS) based method available to cover all classes of methylated metabolites at low detection limits. In this study, we have developed a method for the detection of methylated metabolites, and its biological application. In this approach, we used a HILIC based HPLC method combined with MS to measure methylated organic acids, amino acids, and nucleotides. These metabolites were separated from each other by their hydrophobic interactions and analyzed using a targeted metabolomics approach by single reaction monitoring in positive and negative modes of electrospray ionization. These metabolites were quantified, and the interday reproducibility was ,10% relative standard deviation. Furthermore, by applying this method, we identified high levels of methylated metabolites ...

Polysaccharides from Baizhu were separated by preparative hydrophilic interaction liquid chromatography on an XAmide column and its components were characterised as inulin-type polysaccharides with structures of alpha-D-glucopyranosyl-[-(1 -> 2) -beta-D-fructofuranosyl-](n-1)-(1 -> 2) -beta-D-fructofuranoside (n=3-20) by a combinatory application of electrospray-ionisation mass spectrometry, nuclear magnetic resonance and IR, as well as the chemical analysis of monosaccharide composition. In addition, the contents of nystose and 1F-fructofranosylnystose in the crude and purified Baizhu polysaccharides were determined to be 5.81%, 4.92% and 0.70%, 0.84% (w/w), respectively. In addition, MTT assay indicated that the Baizhu polysaccharides could effectively promote spleen lymphocyte transformation for the enhancement of organism immunity. It is for the first time that inulin-type polysaccharides were discovered in Baizhu and its immuno-enhancing activity was reported, which is a vigorous evidence ...

Immunoassay has been used to measure the blood concentration of drugs, steroids, and vitamin D. However, the immunoassay methods have limitations related to the differences of the methods, variation in the reagents, sensitivity, and specificity. Recently liquid chromatograph mass spectrometers (LC/MS/MS) are being used to improve analytical accuracy and precision based on its superior specificity. On the other hand, in the analysis of biological samples like serum by LC/MS/MS, sample preparation is required to carry out protein precipitation and sample dilution. These procedures cause a risk of variations and mistakes, depending on the operators procedure. In this article, the validation of 25-OH vitamin D2/D3 and steroids in serum using a fully automated sample preparation LC/MS/MS system is described.. Keywords: Sample preparation, Vitamin D, Steroids, LC/MS/MS. ...

Spatial lipid composition, distribution and regulation are very important factors for mediating lipid functionality and, when disrupted, can cause pathophysiological processes leading to cancer, obesity, atherosclerosis, and neurodegeneration. The novel LESAPLUS surface analysis approach combines the standard liquid extraction surface analysis with an additional step of a nano liquid chromatography separation. This combination is ideally suited to investigate small molecule drugs, metabolites or lipids from thin tissue sections.. ...

LIQUID CHROMATOGRAPHY-MASS SPECTROMETRY FOR THE STUDY OF ARACHIDONIC ACID METABOLITES Xiaojing Liu Ian A. Blair, PhD Arachidonic acid (AA) oxidation metabolism has been an important research topic for decades, and numerous oxidation products as well as enzymes involved in AA metabolism together with their downstream metabolites have been identified, although unknown pathways still remain to be characterized. In the present a study a new AA metabolite, 11-oxo-eicosatetraenoic acid (ETE), generated from a major product of cyclooxygenase (COX-2), 11(R)-hydroxyeicosatetraenoic acid (HETE), through 15-hydroxyprostaglandine dehydrogenase (15-PGDH)-mediated oxidation. 11-Oxo-ETE was found to have an anti-proliferative effect on human umbilical vein endothelial cells (HUVECs), with a similar IC50 to a well- known anti-inflammatory mediator, 15-deoxy-12,14-prostaglandin J2 (15d-PGJ2). It was also found that 11-oxo-ETE could be inactivated through the glutathione-S-transferase (GST)/glutathione (GSH) pathway

Fibroblast growth factor 23 (FGF23) is a bone-derived hormone that controls blood phosphate levels by increasing renal phosphate excretion and reducing 1,25-dihydroxyvitamin D3 [1,25(OH)2D] production. Disorders of FGF23 homeostasis are associated with significant morbidity and mortality, but a fundamental understanding of what regulates FGF23 production is lacking. Because the kidney is the major end organ of FGF23 action, we hypothesized that it releases a factor that regulates FGF23 synthesis. Using aptamer-based proteomics and liquid chromatography-mass spectrometry-based (LC-MS-based) metabolomics, we profiled more than 1600 molecules in renal venous plasma obtained from human subjects. Renal vein glycerol-3-phosphate (G-3-P) had the strongest correlation with circulating FGF23. In mice, exogenous G-3-P stimulated bone and bone marrow FGF23 production through local G-3-P acyltransferase-mediated (GPAT-mediated) lysophosphatidic acid (LPA) synthesis. Further, the stimulatory effect of G-3-P ...

The carotenoid test allows one to build a simple classification map of stationary phases used in reversed‑phase liquid chromatography, on the basis of the shape recognition (plotted on the x axis), the polar surface activity (plotted on the y axis), and the phase hydrophobicity (related by the bubble size).

Reverse Phase Liquid Chromatography the most popular process and used in 80% of methods. Advanced chromatographers use advanced forms of RP-chromatography

The Sustainable Environment Research Centre (SERC) undertakes national and world-leading research into waste treatment and the sustainable production of energy from waste and grown biomass. To achieve this, considerable investment has been made into the facilities available to researchers and students.. Waste Water Treatment and Fermentative Hydrogen Production Laboratory. This is a dedicated laboratory for the development and testing of lab scale bio-reactors. Research undertaken includes the optimisation of hydrogen and methane production from various waste substrates, and has been key to the successful development of several field-scale systems.. Ultra Performance Liquid Chromatography Laboratory. SERC is one of only a handful of sites in the UK to be undertaking environmental research using state-of-the-art Ultra Performance Liquid Chromatography / Mass Spectrometry (UPLC-MS). This analytical method provides highly accurate results to nano-gram concentrations. The equipment is currently ...

Dittmar, T. , Whitehead, K. , Minor, E. C. and Koch, B. (2007): Tracing terrigenous dissolved organic matter and its photochemical decay in the ocean by using liquid chromatography/mass spectrometry , Marine chemistry ...

When using the Caco-2 model, the analysis of phenolic compounds may be a challenge for those presenting low uptake rates, as well as the determination of cellular accumulation or metabolism is not an easier task. In this sense, the combination of nano-liquid chromatography \(nano-LC) with high re...

LC/MS analysis of the chimeric OMT reaction products using laudanosoline as a substrate. Upper panel; OMT reactions and their predicted ions in LC/MS analysis.

...With the advent of liquid chromatography/ mass spectrometry and inform... Abstract ... The Q TRAP instrument is based on a triple quadrupole ion path and is... ...,Simultaneously,characterizing,and,quantifying,chloramphenicol,and,its,metabolite,using,LC/MS/MS,biological,advanced biology technology,biology laboratory technology,biology device technology,latest biology technology

New Thermo Scientific Tox Explorer Collection provides instruments, columns and consumables with reliable and validated methods for reproducible results.

Close The Infona portal uses cookies, i.e. strings of text saved by a browser on the users device. The portal can access those files and use them to remember the users data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser. ...

Note: *The Download PDF brochure only consist of Table of Content (ToC), Research Framework of the actual report, and Research Methodology adopted for it ...

Technique by which a mixture of analytes is separated into individual components by liquid chromatography (typically high-performance liquid chromatography),

This application brief demonstrate the unique ability of charged surface hybrid (CSH Technology) C18 to produce high peak capacity peptide separations at high mass loads in nanoLC chromatography

Liquid chromatography with tandem mass spectrometry (LC-MS/MS) based quantitative proteomics provides the relative different protein abundance in healthy and disease-afflicted patients, which offers the information for molecular interactions, signaling pathways, and biomarker identification to serve the drug discovery and clinical research. Typical analysis workflow begins with the peptide feature detection and intensity calculation from LC-MS map. We are the first to propose a deep learning based model, DeepIso, that combines recent advances in Convolutional Neural Network (CNN) and Recurrent Neural Network (RNN) to detect peptide features of different charge states, as well as, estimate their intensity. Existing tools are designed with limited engineered features and domain-specific parameters, which are hardly updated despite a huge amount of new coming proteomic data. On the other hand, DeepIso consisting of two separate deep learning based modules, learns multiple levels of representation ...

Capillary columns (50, 75 and 100 μm I.D.) were packed with silica C₁₈ sub-2 μm particles for 50mm and were employed in nano-liquid chromatography (nano-LC) for

TY - JOUR. T1 - Optimized extraction of phospholipids and lysophospholipids for nanoflow liquid chromatography-electrospray ionization-tandem mass spectrometry. AU - Byeon, Seul Kee. AU - Lee, Ju Yong. AU - Moon, Myeong Hee. PY - 2012/1/21. Y1 - 2012/1/21. N2 - The efficiencies of four different methods for the extraction of phospholipids (PLs) and lysophospholipids (LPLs) from human plasma samples were examined by comparing extraction recovery values using nanoflow liquid chromatography-electrospray ionization-mass spectrometry (nLC-ESI-MS). For recovery measurements, six PL and six LPL standards of different head groups were spiked into a human plasma sample, and the peak areas of each individual species after extraction were measured from the chromatograms of the nLC-ESI-MS runs. Recovery was calculated by comparing the peak area of an extracted standard species with that of the same species spike after extraction of the same plasma sample. For lipid extraction, four different extraction ...

A quantitative, selective and fast ultra-high performance liquid chromatography tandem mass spectrometry method for the simultaneous analysis of 33 basic drugs in hair (amphetamines, cocaine, opiates, opioids and metabolites)

Florentina Laura Chiriac, Iuliana Paun, Florinela Pirvu, Luoana Florentina Pascu, Marcela Niculescu, Toma Galaon - Liquid Chromatography Tandem Mass Spectrometry Method for Ultra-Trace Analysis of Organic UV Filters in Environmental Water Samples

TY - JOUR. T1 - Comparison of gas chromatography-mass spectrometry and liquid chromatography-tandem mass spectrometry methods to quantify α-tocopherol and αtocopherolquinone levels in human plasma. AU - Mottier, Pascal. AU - Gremaud, Eric. AU - Guy, Philippe A.. AU - Turesky, Robert J.. PY - 2002/2/1. Y1 - 2002/2/1. N2 - Two mass spectrometric methods were established for the quantitative analyses of α-tocopherol (TH) and its oxidation product α-tocopherolquinone (TQ) in human plasma. Both methods make use of isotopically labeled internal standards of different levels of deuteration (d3-TH and d6-TQ). Plasma (100 μl) was saponified in the presence of a mixture of antioxidants, and then TH and TQ were extracted with hexane. With the GC-MS method, the analytes were first converted into O-trimethylsilyl derivatives before analysis in the selective ion monitoring mode. The derivatization procedure led to the quantitative conversion of TQ into the O-trimethylsilyl derivative of ...

A novel liquid chromatography-tandem mass spectrometry method is described for the quantitative determination of the endogenous CYP 3A4/5 marker 4β-hydroxycholesterol in human K(2)-EDTA plasma. It is based on alkaline hydrolysis to convert esterified to free 4β-hydroxycholesterol, followed by analyt …

We have demonstrated an on-line laser ablation sampling system and coupling of the system to liquid chromatography (LC) using an infrared (IR) laser to ablate and transfer materials into a flowing solvent stream. With this approach, samples are depos

RATIONALE Neonicotinoids (NNIs) are the fastest expanding group of pesticides in the world over the last two decades; however, they may be a significant contributing factor to bee mortality. The widespread use of NNIs makes it critical to monitor their residuals in the environment. Published methods for NNI analysis are mainly focused on agricultural and food products, and many of them only measured a portion of the commercially available NNIs. METHODS Utilizing a biphenyl stationary-phase column, a sensitive liquid chromatography/tandem mass spectrometry (LC/MS/MS) method was developed to determine eight NNIs, including acetamiprid, clothianidin, dinotefuran, flonicamid, imidacloprid, nitempyram, thiacloprid and thiamethoxam in environmental water. Two multiple reaction monitoring (MRM) transitions were monitored for each compound to ascertain true positive identification. Isotope-labelled NNIs, d3-acetamiprid, d3-clothianidin, d4-imidacloprid and d3-thiamethoxam, were used to compensate for

Abstract: A liquid chromatography tandem mass spectrometry method was developed for quantifying ten cannabinoids in oral fluid (OF). This method utilizes OF collected by the Quantisal device and concurrently quantifies cannabinol (CBN), cannabidiol (CBD), Δ9-tetrahydrocannabinol (THC), 11-hydroxy-Δ9-THC (11-OH-THC), 11-nor-9-carboxy-Δ9-THC (THC-COOH), 11-nor-9-carboxy-Δ9-THC glucuronide (THC-COOH-gluc), Δ9-THC glucuronide (THC-gluc), cannabigerol (CBG), tetrahydrocannabiverin (THCV), and Δ9-tetrahydrocannabinolic acid A (THCA-A). Solid phase extraction was optimized using Oasis Prime HLB 30 mg 96-well plates. Cannabinoids were separated by liquid chromatography over a BEH C18 column and detected by a Waters TQ-S micro tandem mass spectrometer. The lower limits of quantification (LLOQ) were 0.4 ng/mL for CBN, CBD, THC, 11-OH-THC, THC-gluc, and THCV; and 1.0 ng/mL for THC-COOH, THC-COOH-gluc, CBG and THCA-A. Linear ranges extended to 2000 ng/mL for THC and 200 ng/mL for all other analytes. ...

TY - JOUR. T1 - Analysis of metribuzin and its metabolites in livestock products and seafoods by liquid chromatography-tandem mass spectrometry. AU - Kai, Shigemi. AU - Akaboshi, Takeshi. AU - Waki, Masumi. AU - Fuzimaki, Teruhisa. AU - Kanazawa, Hideko. PY - 2011/2. Y1 - 2011/2. N2 - A method for simultaneous determination of metribuzin (MET) and three metribuzin metabolites in livestock products and seafoods by liquid chromatography-tandem mass spectrometry (LC-MS/MS) was developed. MET and its metabolites were extracted from a sample with acetonitrile, followed by InertSepC18 and BondElut SAX cartridge cleanup. The LC separation was performed on a C18 column using 0.01 mol/L ammonium formate-acetonitrile-methanol (70 : 21 : 9) as the mobile phase and MS detection with both positive and negative ion electrospray ionization. The mean recoveries from 10 livestock products and seafoods were generally ,60%, and the relative standard deviations were ,20%.. AB - A method for simultaneous ...

PubMed comprises more than 30 million citations for biomedical literature from MEDLINE, life science journals, and online books. Citations may include links to full-text content from PubMed Central and publisher web sites.

TY - JOUR. T1 - Validation of a high throughput method for serum/plasma testosterone using liquid chromatography tandem mass spectrometry (LC-MS/MS). AU - Singh, Ravinder Jit. PY - 2008/12/12. Y1 - 2008/12/12. N2 - Testosterone, the major androgenic hormone in humans, is commonly measured to aid in the diagnosis of clinical conditions related to its excess or deficiency. In addition, testosterone measurements are used to monitor testosterone replacement-, or antiandrogen therapy. Most commonly, automated direct immunoassays have been used to measure testosterone in human serum. Their advantage compared with other methodologies, lies in high- and rapid sample throughput with minimal human intervention. However, many automated testosterone immunoassays suffer from poor accuracy at the low concentration levels (,50 ng/dL) seen in women and children, or in men undergoing anti-androgen therapy. Our objective was to develop a LC-MS/MS method which measures testosterone in human serum while fulfilling ...

The obligate intracellular lifestyle of Plasmodium falciparum and the difficulties in obtaining sufficient amounts of biological material have hampered the study of specific metabolic pathways in the malaria parasite. Thus, for example, the pools of sugar nucleotides required to fuel glycosylation reactions have never been studied in-depth in well-synchronized asexual parasites or in other stages of its life cycle. These metabolites are of critical importance, especially considering the renewed interest in the presence of N-, O-, and other glycans in key parasite proteins. In this work, we adapted a liquid chromatography tandem mass spectrometry (LC-MS/MS) method based on the use of porous graphitic carbon (PGC) columns and MS-friendly solvents to quantify sugar nucleotides in the malaria parasite. We report the thorough quantification of the pools of these metabolites throughout the intraerythrocytic cycle of P. falciparum The sensitivity of the method enabled, for the first time, the targeted ...

Liquid chromatography tandem mass spectrometry is one of the most specific techniques available in clinical laboratories. In the past, immunoassays were the primary methodology for analysis of steroids in biological samples because they are rapid and easy to perform. However, these methods were shown to suffer from the lack of specificity for measuring many of the diagnostically important steroids. LC-MS/MS overcomes many of the limitations of immunoassays, enhances diagnostic utility of the testing, and expands diagnostic capabilities in endocrinology. In addition to the superior quality of the measurements, LC-MS/MS allows high throughput testing using small sample volume with minimal sample preparation, and frees the laboratory from dependence on suppliers of assay specific reagents. LC-MS/MS is being widely employed for routine measurement of steroids, and the methodology plays an important role in the standardization and harmonization of measurements among clinical laboratories.. ...

A highly sensitive and selective liquid chromatography-mass spectrometry (LC-MS) method has been developed for the determination of epirubicin in serum and c...

A stereoselective, sensitive and rapid liquid chromatography-tandem mass spectrometry (LC-MSMS) method for the determination of R-acenocoumarol and S-acenocoumarol in human plasma was developed and validated at IPRC bioanalytical labs. The procedure involved solid phase extraction of both enantiomers and their corresponding internal standard. The chromatographic separation was accomplished employing a chiral column and proper mobile phase. Detection was carried out using Waters Micromass® Quattro Premier mass spectrometer in multiple reaction monitoring (MRM) mode using turbo ion spray with negative ionization. The method was validated over a linear range of 0.40 - 40.00 ng/ml for R-acenocoumarol and 0.20 - 20.00 ng/ml for the S-acenocoumarol. Method validation covered different parameters such as linearity, accuracy, precision and stability. The method was successfully applied for the determination of R and S-acenocoumarol in plasma samples of 28 healthy subjects who participated in a pharmacokinetics

TY - JOUR. T1 - Reference ranges for testosterone in men generated using liquid chromatography tandem mass spectrometry in a community-based sample of healthy nonobese young men in the framingham heart study and applied to three geographically distinct cohorts. AU - Bhasin, Shalender. AU - Pencina, Michael. AU - Jasuja, Guneet Kaur. AU - Travison, Thomas G.. AU - Coviello, Andrea. AU - Orwoll, Eric. AU - Wang, Patty Y.. AU - Nielson, Carrie. AU - Wu, Frederick. AU - Tajar, Abdelouahid. AU - Labrie, Fernand. AU - Vesper, Hubert. AU - Zhang, Anqi. AU - Ulloor, Jagadish. AU - Singh, Ravinder. AU - DAgostino, Ralph. AU - Vasan, Ramachandran S.. PY - 2011/8/1. Y1 - 2011/8/1. N2 - Context: Reference ranges are essential for partitioning testosterone levels into low or normal and making the diagnosis of androgen deficiency. We established reference ranges for total testosterone (TT) and free testosterone (FT) in a community-based sample of men. Methods: TT was measured using liquid chromatography ...

An improved method for determining levels of levosulpiride in human plasma using ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) was developed and validated. The protein precipitation method was used for plasma sample preparation. Levosulpiride and an internal standard (IS) were isocratically separated on a UPLC BEN C(18) column with a mobile phase of ammonium formate buffer (1 mM, adjusted to pH 3 with formic acid) and acetonitrile (60:40, v/v). MS/MS detection was performed by monitoring the parent -, daughter pair of levosulpiride and the IS at m/z 342 -, 112 and 329 -, 256, respectively. The method was linear from 2.5 to 200 ng/mL and exhibited acceptable precision and percent recovery. The method was successfully demonstrated in pharmacokinetic and bioequivalence studies of two levosulpiride oral formulations administered to healthy volunteers. When compared to the previous LC-MS methods, the proposed method is faster, well-validated, and uses lesser plasma ...

Carbamazepine (CBZ) and oxcarbazepine (OXCBZ) are both antiepileptic drugs, which are prescribed as first-line drugs for the treatment of partial and generalized tonic-clonic epileptic seizures. In this paper, a specific and sensitive liquid chromatography-electrospray ionization mass spectrometry m …

TY - JOUR. T1 - Effect of ionization modifiers on the simultaneous analysis of all classes of phospholipids by nanoflow liquid chromatography/tandem mass spectrometry in negative ion mode. AU - Bang, Dae Young. AU - Lim, Sangsoo. AU - Moon, Myeong Hee. N1 - Funding Information: This study was supported by the National Research Foundation (NRF) of Korea grant (No. 2011-0016438 ) funded by the Korean government (MEST) and in part by a grant (No. 2011-0001125 ). PY - 2012/6/1. Y1 - 2012/6/1. N2 - The effect of ionization modifiers added to the mobile phase of nanoflow liquid chromatography-tandem mass spectrometry (nLC-ESI-MS 3) on the simultaneous analysis of all phospholipid (PL) classes in negative ion mode has been investigated. While MS analysis of most PL classes is carried out in negative ion mode, analysis of neutral polar (polar but electrically neutral) lipids like phosphatidylcholine (PC) and sphingomyelin (SM) is highly efficient in positive ion mode. Therefore, analysis of PL mixture ...

SICHILONGO, Kwenga F.; MUCKOYA, Vallerie A. y NINDI, Mathew M.. A rapid and sensitive LC-MS/MS method for the determination of multi-class residues of antibiotics in chicken liver. S.Afr.j.chem. (Online) [online]. 2015, vol.68, pp.01-06. ISSN 1996-840X. http://dx.doi.org/10.17159/0379-4350/2015/v68a1.. A very sensitive, simple and cost-effective liquid chromatography-mass spectrometry/mass spectrometry (LC-MS/MS) method for the determination of multi-class antibiotics in chicken liver was developed. The drugs under consideration were sulfaguanidine and sulfamethazole, trimethoprim, tetracycline, chlortetracycline and tylosin. Linear calibrations were established for all the analytes and the R2 values ranged between 0.9990 and 0.9997. The limits of quantitation (LOQs) varied between 0.025 and 78.8 μg kg-1. The limit of detections (LODs) were better than those that have been reported for the same antibiotics in many instances in other studies and ranged between 0.010-31.5 μg kg-1 with the ...

SICHILONGO, Kwenga F.; MUCKOYA, Vallerie A. e NINDI, Mathew M.. A rapid and sensitive LC-MS/MS method for the determination of multi-class residues of antibiotics in chicken liver. S.Afr.j.chem. (Online) [online]. 2015, vol.68, pp.01-06. ISSN 1996-840X. http://dx.doi.org/10.17159/0379-4350/2015/v68a1.. A very sensitive, simple and cost-effective liquid chromatography-mass spectrometry/mass spectrometry (LC-MS/MS) method for the determination of multi-class antibiotics in chicken liver was developed. The drugs under consideration were sulfaguanidine and sulfamethazole, trimethoprim, tetracycline, chlortetracycline and tylosin. Linear calibrations were established for all the analytes and the R2 values ranged between 0.9990 and 0.9997. The limits of quantitation (LOQs) varied between 0.025 and 78.8 μg kg-1. The limit of detections (LODs) were better than those that have been reported for the same antibiotics in many instances in other studies and ranged between 0.010-31.5 μg kg-1 with the ...

Busulfan is an alkylating agent widely used in the ablation of bone marrow cells before hematopoietic stem cell transplant. Due to large intraindividual and interindividual variations, and narrow therapeutic window, therapeutic drug monitoring of busulfan is warranted. A quick and reliable HPLC-MS/MS method was developed for the assay of plasma busulfan. HPLC involved C18 column, and MS/MS was used in electrospray ionization (ESI) positive mode. Quantitation and identification of busulfan was made using various multiple reactions monitoring (MRMs). Isotopic labeled busulfan-d8 was used as the internal standard. The method is linear from 50 to 2500 ng/mL and has with-in run and between-run imprecision of |10|%.

Sigma-Aldrich offers abstracts and full-text articles by [Gabriela Peste, Nela Bibire, Mihai Apostu, Aurel Vlase, Corneliu Oniscu].

An original liquid chromatography-tandem mass spectrometry (LC-MS-MS) method coupled to online extraction has been developed for cyanide determination in blood. A method involving fluorimetric detection after naphthalene-2,3-dicarboxyaldehyde (NDA) complexation by taurine in the presence of cyanide was previously described. Its performance was limited because of the absence of an internal standard (IS). Using cyanide isotope 13C15N as IS allowed quantification in MS-MS. After the addition of 13C15N, 25 µL of blood were diluted in water and deproteinized with methanol. Following derivatization with NDA and taurine for 10 min at 4°C, 100 µL was injected into the online LC-MS-MS system. An Oasis HLB was used as an extraction column, and a C18 Atlantis was the analytical column. The chromatographic cycle was performed with an ammonium formate (20 mM, pH 2.8) (solvent A) and acetonitrile/solvent A (90:10, v/v) gradient in 6 min. Detection was performed in negative electrospray ionization mode ...

A precise HPLC/MS/MS approach; Lipidomics in Diabetes and the Metabolic Syndrome; LC-MS-MS research of impartial Eicosanoids; Quantification Of F2-Isoprostanes In organic Fluids And Tissues As A degree Of Oxidant rigidity; dimension of goods of Docosahexaenoic Acid Peroxidation, Neuroprostanes, and Neurofurans; Enantiomeric separation of hydroxy and hydroperoxy eicosanoids through chiral column chromatography; exact Chiral Lipidomics research by means of Liquid Chromatography Electron seize Atmospheric strain Chemical Ionization Mass Spectrometry (LC-ECAPCI/MS); Shotgun Lipidomics by means of Tandem Mass Spectrometry lower than Data-Dependent Acquisition keep an eye on; id of Intact Lipid Peroxides via Ag+ Coordination Ionspray Mass Spectrometry (CIS-MS); Quantification of Cardiolipin by means of Liquid Chromatography Electrospray Ionization Mass Spectrometry ...

TY - JOUR. T1 - Performance metrics for liquid chromatography-tandem mass spectrometry systems in proteomics analyses. AU - Rudnick, Paul A.. AU - Clauser, Karl R.. AU - Kilpatrick, Lisa E.. AU - Tchekhovskoi, Dmitrii V.. AU - Neta, Pedatsur. AU - Blonder, Nikša. AU - Billheimer, Dean D.. AU - Blackman, Ronald K.. AU - Bunk, David M.. AU - Cardasis, Helene L.. AU - Ham, Amy Joan L.. AU - Jaffe, Jacob D.. AU - Kinsinger, Christopher R.. AU - Mesri, Mehdi. AU - Neubert, Thomas A.. AU - Schilling, Birgit. AU - Tabb, David L.. AU - Tegeler, Tony J.. AU - Vega-Montoto, Lorenzo. AU - Variyath, Asokan Mulayath. AU - Wang, Mu. AU - Wang, Pei. AU - Whiteaker, Jeffrey R.. AU - Zimmerman, Lisa J.. AU - Carr, Steven A.. AU - Fisher, Susan J.. AU - Gibson, Bradford W.. AU - Paulovich, Amanda G.. AU - Regnier, Fred E.. AU - Rodriguez, Henry. AU - Spiegelman, Cliff. AU - Tempst, Paul. AU - Liebler, Daniel C.. AU - Stein, Stephen E.. PY - 2010/2. Y1 - 2010/2. N2 - A major unmet need in LC-MS/MS-based ...

TY - JOUR. T1 - Bioanalysis of 6-diazo-5-oxo-l-norleucine in plasma and brain by ultra-performance liquid chromatography mass spectrometry. AU - Alt, Jesse. AU - Potter, Michelle C.. AU - Rojas, Camilo. AU - Slusher, Barbara. PY - 2015/4/1. Y1 - 2015/4/1. N2 - Glutamine is an abundant amino acid that plays pivotal roles in cell growth, cell metabolism, and neurotransmission. Dysregulation of glutamine-using pathways has been associated with pathological conditions such as cancer and neurodegenerative diseases. 6-Diazo-5-oxo-l-norleucine (DON) is a reactive glutamine analog that inhibits enzymes affecting glutamine metabolism such as glutaminase, 2-N-amidotransferase, l-asparaginase, and several enzymes involved in pyrimidine and purine de novo synthesis. As a result, DON is actively used in preclinical models of cancer and neurodegenerative disease. Moreover, there have been several clinical trials using DON to treat a variety of cancers. Considerations of dose and exposure are especially ...

GE AKTA fast protein liquid chromatography system is an eagle-i resource of type Fast protein liquid chromatography instrument at Universidad Central del Caribe.

Liquid Chromatography / Tandem Mass Spectrometry (LS/MS/MS). Liquid chromatography/tandem mass spectrometry provides identification of analytes of interest within a mixture based on retention time and characteristic parent/daughter ion fragmentation patterns, which provides the compounds unique molecular fingerprint. When liquid chromatography is suitable for separation of compounds, LC/MS/MS can provide significantly greater sensitivity than the corresponding gas chromatography/mass spectrometry (i.e., GC/MS). KorvaLabs employs LC/MS/MS for the identification of substances in white powders - such as in the case of certification of dietary supplements - and for certain compounds in urine where GC/MS is not sufficient.. Gas Chromatography / Mass Spectrometry (GC/MS). Like LC/MS, the related gas chromatography/mass spectrometry (i.e., GC/MS)provides identification based on retention time and ion fragmentation patterns; however, GC/MS… KorvaLabs uses GC/MS for the detection of most banned ...

Detection Of Biomarkers in Cerebrospinal Fluid of Multiple Sclerosis Patients By Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS ...

Steuer, Andrea E; Poetzsch, Michael; Stock, Lorena; Eisenbeiss, Lisa; Schmid, Yasmin; Liechti, Matthias E; Kraemer, Thomas (2017). Development and validation of an ultra-fast and sensitive microflow liquid chromatography-tandem mass spectrometry (MFLC-MS/MS) method for quantification of LSD and its metabolites in plasma and application to a controlled LSD administration study in huma. Drug Testing and Analysis, 9(5):788-797. ...

We report here a simple and rapid method for the quantification of brominated vegetable oil (BVO) in soft drinks based upon liquid chromatography-electrospray ionization mass spectrometry. Unlike previously reported methods, this novel method does not require hydrolysis, extraction or derivatization steps, but rather a simple dilute and shoot sample preparation. The quantification is conducted b ...

University of Leicester researchers writing in the journal Chemical Research in Toxicology say they have found convincing evidence that cannabis smoke damages DNA and it could potentially increase the risk of cancer development in humans.Using a newly developed highly sensitive liquid chromatography-tandem mass spectrometry method, the University

Disease-specific compounds (biomarkers) are analyzed in clinical laboratories to assist with diagnosing diseases. This thesis describes development and validation of liquid chromatography tandem mass spectrometry (LC-MS/MS) based tests for diagnosing a diverse group of endocrine and metabolic diseases. The analytical methods used on-line and off-line sample extraction and analytical derivatization as means of enhancing the analytical sensitivity, specificity and clinical utility. All developed methods were extensively validated and reference intervals for the biomarker concentrations were established in blood samples of healthy adults and children. Advantages of the LC-MS/MS as an analytical technique include possibility of simultaneous measurement of multiple analytes and ability of confirming their identity. In this thesis we proposed and evaluated approaches for the assessment of the specificity of analysis in the methods that use tandem mass spectrometry detection. To enhance throughput of ...

Abstract To support therapeutic drug monitoring of patients with cancer, a fast and accurate method for simultaneous quantification of the registered anticancer drugs afatinib, axitinib, ceritinib, crizotinib, dabrafenib, enzalutamide, regorafenib and trametinib in human plasma using liquid chromatography tandem mass spectrometry was developed and...

In this study, the anti-melanogenesis efficacy of clinically used herbal prescription LASAP-C, which consists of four herbal medicines-Rehmanniae Radix Crudus, Lycii Fructus, Scutellariae Radix, and Angelicae Dahuricae Radix, was investigated. The chemical profile of LASAP-C was established by conducting ultra-performance liquid chromatography-electrospray ionization-mass spectrometry. Anti-melanogenic efficacy was evaluated by tyrosinase, tyrosinase-related protein (TRP)-1, and TRP-2 expression in B16F10 melanoma cells. In vivo evaluation was performed by using zebrafish model. Molecular evidences suggested that melanin synthesis was inhibited via the down-regulation of tyrosinase, tyrosinase-related protein (TRP)-1, and TRP-2 expression in B16F10 melanoma cells treated with LASAP-C. The anti-melanogenesis efficacy was also confirmed in vivo by using the zebrafish model. The results of this study provide strong evidences that LASAP-C can be used as an active component in cosmeceutical products for

In this study, we developed the stable isotope dilution hydrophilic interaction liquid chromatography with tandem mass spectrometry (HILIC-MS/MS) technique for the accurate, reasonable and simultaneous quantification of glutamic acid (Glu), glutamine (Gln), pyroglutamic acid (pGlu), γ-aminobutyric acid (GABA) and theanine in mouse brain tissues. The quantification of these analytes was accomplished using stable isotope internal standards and the HILIC separating mode to fully correct the intramolecular cyclization during the electrospray ionization. It was shown that linear calibrations were available with high coefficients of correlation (r(2) | 0.999, range from 10 pmol/mL to 50 mol/mL). For application of the theanine intake, the determination of Glu, Gln, pGlu, GABA and theanine in the hippocampus and central cortex tissues was performed based on our developed method. In the region of the hippocampus, the concentration levels of Glu and pGlu were significantly reduced during reality-based theanine

A polyacrylamide (PAAm)-modified monolithic silica capillary column of increased phase ratio, 200T-PAAm, for hydrophilic interaction liquid chromatography (HILIC) was prepared. The column showed high separation efficiency, with a theoretical plate height H = 7â€20 μm at a linear velocity, u = 1â€7 mm/s. From a kinetic plot analysis, it was expected that the monolithic column could provide three times faster separation than particle-packed HILIC columns under a pressure limit at 20 MPa. HILIC coupled with electrospray ionization (ESI)â€mass spectrometry (HILIC-ESI-MS) using the 200T-PAAm column was employed for the analysis of underivatized carbohydrates to achieve fast and efficient separations of mixtures containing mono-, di-, and trisaccharides within 5 min. Under single MS full scan mode, 200 pg of oligosaccharides was detected by the system. The limit of detection (LOD) of the LC-ESI-MS/MS system was determined using selected reaction monitoring (SRM) to be as low as 3.2 ...

1,2-Dehydro-N-acetyldopamine (dehydro NADA) and its derivatives have been identified as important cuticular sclerotizing precursors responsible for the hardening of the exoskeleton of soft-bodied insects. In addition, these compounds may serve as precursors in the biosynthesis of the large number of bioactive compounds present in the exoskeleton of marine invertebrates. In this work the products of non-enzymatic oxidation of 1,2-dehydro N-acyldopamine were examined using reversed-phase high performance liquid chromatography/electrospray/tandem mass spectrometry (RP-HPLC/ESI/MS-MS). In addition, the role of tyrosinase-catalyzed oxidation of dehydro-N-acetyldopamine in the cross-linking of cuticle proteins was studied by examining two thiol-containing nucleophiles and a model peptide using RP- HPLC/ESI/MS-MS. Finally, the tyrosinase-catalyzed oxidative cyclization and polymerization of N-acetyl-1,2-dehydro Dopa was examined as a possible biosynthetic pathway for forming bioactive compounds called

ePIC (electronic Publication Information Center) is the official repository for publications and presentations of Alfred Wegener Institute for Polar and Marine Research (AWI)

We report the refinement of a high-throughput, liquid chromatography/mass spectrometry (LC/MS)-based screening method for the identification of ...

Learn about Agilent׷ liquid chromatography/mass spectrometry (LC/MS). Agilent LC/MS enables a wide array of applications by combining sample preparation, liquid chromatography (LC), mass spectrometry (MS), and dedicated software tools like compound databases and libraries.

Detailed HPLC/MS/MS studies on blood samples collected from normal healthy human subjects were performed to generate a reference of sphingolipid (SPL) levels for future investigations into diseases utilizing blood as a matrix. The impact of sample collection (serum, plasma, and anticoagulants), attributes of blood donors (gender, fasting state) and handling of blood were investigated. In addition, the SPL metabolomic profiles (18C sphingoid backbone, C14 to C26 N-acyl chain) of human plasma were determined. Blood was collected from healthy males and non-pregnant females under fasting and nonfasting conditions with and without various anticoagulants (EDT A, citrate and heparin). Plasma prepared with EDT A was determined to be ideal over the other blood formulations for SPL analyses, yielding the lowest variances in determination of most analyzed SPL classes. Sph1 P levels were higher in serum than plasma (0.67~M vs. 0.32jJM) with no effect on other SPLs in EDTA plasma. There were no variances on ...

Journal of Chemistry is a peer-reviewed, Open Access journal that publishes original research articles as well as review articles on all aspects of fundamental and applied chemistry.

Manufacturer of Liquid Chromatography Mass Spectrometry - LCMS QQQ 6460 Mass Spectrometer, CAH Mass Solution offered by Trivitron Healthcare Pvt. Ltd., Chennai, Tamil Nadu.

Many direct immunoassays in use today for testosterone analysis are little better than a guess at the low levels that are sometimes required.  This has led many clinical societies to adv

The nearly 50% production capacity increase is in response to growing global demand for purification media from the antibody drug manufacturing industry.. At a cost of approximately ¥5 billion, the Nanyo Complexs Toyopearl production facilities are being expanded. Construction began in October 2016 and is slated for completion in August 2018. Commercial operations at the expanded production facilities are expected to commence in April 2019.. Liquid chromatography separation and purification media are used in the production of biopharmaceutical ingredients. Employing differences in charge, hydrophobicity, specific affinity, and molecular size, these media are designed to separate and purify target components. Given the rapid growth of the market for biopharmaceutical products, in Japan, the United States, and countries in Europe and in China, India, and other emerging nations, these media are in high demand. And Tosoh is committed to meeting that demand.. With its high strength, superior ...