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ADME/Pharmacokinetic Studies from Serum and Plasma: Improvements in Sample Preparation and LC–MS Analysis of Therapeutic OligonucleotidesThe paramount problem in performing absorption, distribution, metabolism, and excretion (ADME)/pharmacokinetic studies of therapeutic oligonucleotides revolves around inefficient and labor-intensive sample preparation. These traditional methods require multiple steps - liquid–liquid extraction (LLE) and solid-phase extraction (SPE) - to extract therapeutic oligonucleotides from serum and plasma for liquid chromatography–mass spectrometry (LC–MS) analysis and thus are not practical for clinical studies with large numbers of samples. Furthermore, these methods tend to yield low recoveries and poor reproducibility. This article presents a revolutionary new method for performing sample cleanup of therapeutic oligonucleotides from serum and plasma. The method extracts many types of therapeutic oligonucleotides from biological matrices in a rapid four-step SPE protocol that eliminates the need for LLE and can be automated for large sample sets. In the testing presented, different..
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Metabolite Profiling Applications in Early Drug DiscoveryMetabolite profiling in drug discovery can contribute significantly at the lead optimization stage in two main application areas. The first is the identification of major metabolites, which provides medicinal chemists with information on the metabolic "soft spots." These soft spots are locations on the molecule particularly susceptible to metabolic modification, which can contribute to high pharmacokinetic clearance. This information then can be used to optimize the structure of a lead compound or chemical series to slow the rate of metabolism and therefore reduce hepatic clearance. This improves the absorption, distribution, metabolism, and excretion (ADME) properties of the compound, such as bioavailability, exposure (as measured by area under the curve), and half-life. Through iterative optimization of the structure and timely generation of metabolism data following each structural modification, pharmacokinetic properties can be improved while maintaining activity against the therapeutic target.
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Meeting the Surge in Demand for Seafood Screening on the Gulf CoastThe threat to human health posed by the recent oil spill has created a pressing need for high-throughput seafood analysis to ensure that it does not contain dangerous levels of polycyclic aromatic hydrocarbons (PAHs) and to allow the earliest possible reopening of the fisheries. Adapting QuEChERS sample preparation technology to this application, combined with the use of preconfigured PAH gas chromatography–mass spectrometry analysis systems, can provide the ability to process in a timely manner the enormous number of samples that will be generated by the ongoing testing program.
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Towards Automated Routine Analysis of the Distribution of Trace Elements in Single Cells Using ICP-MSAnalysis of the compositional variation in living cells is essential for understanding biological processes. Single-cell elemental analysis by triple-quadrupole ICP-MS is emerging as a selective, highly sensitive, and potentially high-throughput technique for the study of constitutive elements, and uptake of metallodrugs (or metal-containing nanomaterials) in single cells.
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Increasing Productivity of ADME Studies Using Accurate Mass TechnologyA new time-of-flight mass spectrometer was evaluated for performing simultaneous metabolic stability measurement and metabolite identification with ultrahigh-pressure liquid chromatography. Six representative compounds (clomipramine, diclofenac, imipramine, haloperidol, verapamil, and midazolam) were incubated in rat liver microsomes at a more physiologically relevant substrate concentration (1 ?M). High-resolution full-scan and product-ion spectra were acquired in a single injection using generic methodology. Quantitative clearance of the parent was measured using the full-scan data. Major metabolites were identified using the accurate mass product ion spectra. High scanning speed allowed for a sufficient number of data points to be collected across the chromatographic peak for quantitative analysis. Sensitivity was sufficient for obtaining meaningful kinetics with a 1 ?M initial substrate concentration.
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Using LC–oa-TOF MSE with a Multivariate Statistical Sample Statistical Sample Profiling Strategy to Distinguish Chinese Red Ginseng from Korean Red GinsengBoth Chinese ginseng and Korean ginseng are similar plant species and undergo similar handling procedures when harvested and processed for sale. Despite their similarities, Korean ginseng commands a higher price than Chinese ginseng on the open market and is believed to produce different clinical effects than Chinese ginseng. Chinese researchers are now employing new techniques on the two varieties of ginseng to understand their chemical differences. HPLC/UV-based strategies for distinguishing the two types of ginseng have proven to be mostly ineffective due to lack of resolution. Using UltraPerformance liquid chromatography/orthogonal acceleration (oa)–TOF mass spectrometry and exact mass measurement, the authors developed a high-resolution method using multivariate statistical analysis for separating and identifying differences between Chinese ginseng and Korean ginseng at the molecular level.
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GCxGC with Fluidic Modulation on Enantioselective Oil AnalysisDescribes a novel approach for the enantioselective separation of spearmint oil incorporating a fluidic modulation system.
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Dried Blood Spots and High-Resolution Mass Spectrometry for Discovery Fast PK BioanalysisThis article introduces the advantages of accurate mass high-resolution mass spectrometry LC–MS (HRMS) coupled to the dried blood spot (DBS) technique for fast PK applications in a discovery environment. Compared with the established norm of plasma bioanalysis using triple quadrupoles, HRMS coupled to DBS is a viable alternative. The benefit is access to critical new information (HRMS bioanalysis) and significantly less stress on the animal (DBS), both factors that potentially improve the quality of early PK data.
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Using LC–oa-TOF MSE with a Multivariate Statistical Sample Statistical Sample Profiling Strategy to Distinguish Chinese Red Ginseng from Korean Red GinsengBoth Chinese ginseng and Korean ginseng are similar plant species and undergo similar handling procedures when harvested and processed for sale. Despite their similarities, Korean ginseng commands a higher price than Chinese ginseng on the open market and is believed to produce different clinical effects than Chinese ginseng. Chinese researchers are now employing new techniques on the two varieties of ginseng to understand their chemical differences. HPLC/UV-based strategies for distinguishing the two types of ginseng have proven to be mostly ineffective due to lack of resolution. Using UltraPerformance liquid chromatography/orthogonal acceleration (oa)–TOF mass spectrometry and exact mass measurement, the authors developed a high-resolution method using multivariate statistical analysis for separating and identifying differences between Chinese ginseng and Korean ginseng at the molecular level.
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Asymmetrical Flow FFF as an Analytical Tool for the Investigation of the Physical Stability of Virus-Like ParticlesThe rational development of AF4 methods for the investigation of VLP is illustrated.
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Tips & Tricks GPC/SEC: How GPC/SEC Can Help to Reduce PET Plastic WasteOne of the major problems with plastics is recycling. Only a few materials can be recycled and the acceptance of recyclates is sometimes low. GPC/SEC can be applied to investigate the quality of materials containing recycled portions.
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Simultaneous Headspace-GC–FID Analysis for Methanol and Ethanol in Blood, Saliva, and Urine: Validation of Method and Comparison of SpecimensAn HS-GC-FID method for the determination of ethanol and methanol content in biological fluids is presented.
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A Generic Headspace GC Method for Residual Solvents in Pharmaceutical: Benefits, Rationale, and Adaptations for New Chemical EntitiesA generic static headspace gas chromatographic (HSGC) method for determining common residual solvents in pharmaceuticals is described.
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RAFA 2024 Highlights: Cutting-Edge Chromatography Techniques for Food Safety and Food AnalysisAn illuminating session focusing on progress in analytical techniques used in food analysis took place on Wednesday 6 November 2024 at RAFA 2024 in Prague, The Czech Republic, including a talk on the analysis of 1000 toxins in 10 minutes.
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A Generic Headspace GC Method for Residual Solvents in Pharmaceutical: Benefits, Rationale, and Adaptations for New Chemical EntitiesA generic static headspace gas chromatographic (HSGC) method for determining common residual solvents in pharmaceuticals is described.
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Comparison of Ion Trap and Q-TOF Mass Spectrometers for Protein IdentificationThis study uses the challenging analysis of a complex, multi-organ peptide digest of Caenorhabditis elegans (C. elegans) to compare the performance of a novel linear ion trap mass spectrometer and a quadrupole time-of-flight (Q-TOF) mass spectrometer.
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Chiral Purification with Stacked Injections and Collections Using the Prep 100 SFC MS Directed SystemChiral chromatography has become the preferred tool for enantiomer separations in the early stages of pharmaceutical development for the purpose of accurately identifying single pure enantiomers with pharmacologic, toxicological, and clinical information, as stipulated by the FDA.1
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Online Identification of Flavones from Flos Chrysanthemi by LC–MS-IT-TOFThe use of medicinal herbs as alternative treatment methods continues to grow. With this escalating use has come an increasing interest in determining the chemical compositions of these herbs in order to obtain a better understanding of their makeup and effects. In this study, Flos Chrysanthemi, a commonly used traditional Chinese medicine that has been cultivated for centuries, was analyzed to identify the main flavone compositions in one original breed of Flos Chrysanthemi (Hangbaiju) in China.
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Using Novel TOF-MS to Increase Sensitivity and Confidently Detect Drugs of Abuse in UrineThe analysis of urine for drugs of abuse via chromatographic methods is commonplace but can be complicated by high matrix effects and frequent coelution. Novel time-of-flight mass spectrometry in combination with sophisticated deconvolution software was tested and found to provide increased confidence in results due to the high sensitivity and quality of spectra achieved.
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Adjustment to the Chromatographic System in U.S. Pharmacopeia Monographs: Flexibility and LimitationsTo meet system suitability requirements, chromatographers might need to make adjustments to the high performance liquid chromatography (HPLC) operating conditions.
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Simultaneous Headspace-GC–FID Analysis for Methanol and Ethanol in Blood, Saliva and Urine: Validation of Method and Comparison of SpecimensA simultaneous headspace-GC–FID method was validated to establish methanol and ethanol assessment in blood, urine and saliva.
Latest:
ADME/Pharmacokinetic Studies from Serum and Plasma: Improvements in Sample Preparation and LC–MS Analysis of Therapeutic OligonucleotidesThe paramount problem in performing absorption, distribution, metabolism, and excretion (ADME)/pharmacokinetic studies of therapeutic oligonucleotides revolves around inefficient and labor-intensive sample preparation. These traditional methods require multiple steps - liquid–liquid extraction (LLE) and solid-phase extraction (SPE) - to extract therapeutic oligonucleotides from serum and plasma for liquid chromatography–mass spectrometry (LC–MS) analysis and thus are not practical for clinical studies with large numbers of samples. Furthermore, these methods tend to yield low recoveries and poor reproducibility. This article presents a revolutionary new method for performing sample cleanup of therapeutic oligonucleotides from serum and plasma. The method extracts many types of therapeutic oligonucleotides from biological matrices in a rapid four-step SPE protocol that eliminates the need for LLE and can be automated for large sample sets. In the testing presented, different..
Latest:
Trace-Level Aliphatic Amines in Cationic DrugsThe analytical challenge treated in the present work consists in determining sub-ppb concentrations of low-molecular-weight amines in the presence of strongly retained cationic drugs by using ion chromatography (IC) with upstream in-line coupled-column matrix elimination (CCME).
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Rapid Quality Control of Flavours and Fragrances using Fast GC–MS and Multi-MS Library Search ProceduresUsing narrow-bore column fast GC combined with rapid scanning qMS to analyse flavours and fragrances is described.
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Phosphorylation Site Localization Using Probability-Based ScoringThe development of a phosphorylation probability scoring tool in an automated data search engine resolves ambiguity in site localization when compared to manual methods.
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Buffer Considerations for LC and LC–MSThe authors examine some critical factors with regard to buffers in LC and LC-MS research.
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Popular Cell Expression Systems in the Biotechnology IndustryThe authors describe the most common cell-based protein expression systems and purification strategies used in the biotechnology industry.
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Racing Against Time: High-Throughput Analysis of Dermorphin in Equine UrineThis article examines the problem of dermorphin doping in horse racing and presents an effective method for its detection using LC–MS TQ.
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Light Scattering for the Masses Monoclonal Antibodies and the Preparative Use of Flow Field-Flow Fractionation (AF4)Proteins - especially monoclonal antibodies (MABs) - have become increasingly important in pharmaceutical work. However, there are some important differences between conventional, chemically-synthesized drugs and proteins. Because of the complex and weak structure of proteins, even a slight change in conditions, such as pH value, temperature, or mechanical stress, may lead to aggregation and a loss of activity or stability.
