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Mastering Pressure Management in GPC/SEC SystemsThis installment of Tips & Tricks deals with pressure monitoring for GPC/SEC systems and gives hints for efficient troubleshooting to solve issues that are identified in the laboratory.
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Separation Science: The State of the Art: Field-Flow Fractionation: Extended Frontiers to Supramolecular and Complex Polymer MaterialsIn this extended special feature to celebrate the 35th anniversary edition of LCGC Europe, key opinion leaders from the separation science community explore contemporary trends in separation science and identify possible future developments.
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An LC–MS/MS Method for the Evaluation of Intestinal Permeability in Blood PlasmaA rapid and robust LC–MS/MS method for determining lactulose and rhamnose concentrations in blood plasma was used to determine intestinal permeability from blood plasma, which can help diagnose gastrointestinal diseases such as Crohn’s disease.
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Coupling Chiral Stationary Phases as a Fast Screening Approach for HPLC Method DevelopmentGiven the increasing number of chiral samples and the time constraints under which chromatographers work, choosing an appropriate chiral stationary phase for the resolution of enantiomers can be challenging. In this article, the authors describe a screening approach for chiral HPLC method development.
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Method Development for the Qualitative and Quantitative Analysis of Pesticides by Direct Injection Liquid Chromatography– Tandem Mass Spectrometry (LC–MS/MS)This modification of ASTM method D8026 for pesticides in environmental matrices includes more pesticides and lowers the reporting limits, thus increasing throughput and measurement capacity for a large surface-water monitoring project.
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A Standardized 2D-LC Screening Platform for Peak Purity Determination in Pharmaceutical AnalysisThis study suggests a 2D-LC screening method to evaluate peak purity and ensure specificity in pharmaceutical analysis, thereby promoting the safe production of medicines by detecting active pharmaceutical ingredients (API) and related substances.
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Gas Chromatography–Mass Spectrometry (GC–MS) with Cold Electron Ionization (EI): Bridging the Gap Between GC–MS and LC–MSGas chromatography–mass spectrometry (GC–MS) with cold electron ionization (EI) is based on interfacing the GC and MS instruments with supersonic molecular beams (SMB) along with electron ionization of vibrationally cold sample compounds in SMB in a fly-through ion source (hence the name cold EI). GC–MS with cold EI improves all the central performance aspects of GC–MS. These aspects include enhanced molecular ions, improved sample identification, an extended range of compounds amenable for analysis, uniform response to all analytes, faster analysis, greater selectivity, and lower detection limits. In GC–MS with cold EI, the GC elution temperatures can be significantly lowered by reducing the column length and increasing the carrier gas flow rate. Furthermore, the injector temperature can be reduced using a high column flow rate, and sample degradation at the cold EI fly-through ion source is eliminated. Thus, a greater range of thermally labile and low volatility compounds can be analyzed. The extension of the range of compounds and applications amenable for analysis is the most important benefit of cold EI that bridges the gap with LC–MS. Several examples of GC–MS with cold EI applications are discussed including cannabinoids analysis, synthetic organic compounds analysis, and lipids in blood analysis for medical diagnostics.
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Pushing the Limits of Small Molecule Structural Characterization with High-Resolution Ion Mobility (HRIM)Webinar Date/Time: Thu, Apr 4, 2024 11:00 AM EDT
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A Comparison of CE–MS and LC–MS for Peptide SamplesDespite their different levels of technological maturity, CE and LC coupled with electrospray ionization MS techniques can be operated at the same level of automation. However, they differ in their configuration, selectivity, sensitivity, and method development.
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Physicochemical Methods for Vectors and Ancillary Materials in Cellular and Gene TherapiesCellular and gene therapies (CGTs) have contributed significantly to the improvement of clinical outcomes for patients in the recent years. This paper discusses a range of physicochemical methods that play an important role in the difficult characterization of viral vectors, to meet the unique needs of CGT manufacturing process development, process and product characterization, and the quality control testing of these materials.
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Multivariate Optimization Procedure for Dynamic Headspace Extractions Coupled to GC(×GC)A generalized approach using DoE is presented for the optimization of DHS extraction parameters.
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Liquid Chromatographic Peak Purity Assessments in Forced Degradation Studies: An Industry PerspectiveThis review article discusses scientific rationales and current best practices in the pharmaceutical industry for performing chromatographic peak purity assessments (PPA). These activities are associated with the development and validation of liquid chromatographic (LC) stability-indicating analytical methods applicable to regulatory submissions of small-molecule drug candidates. The discussion includes a comprehensive overview of the PPA-related regulatory and scientific landscape and common industry approaches to obtain PPA results, as well as the strengths and weaknesses of PDA-facilitated ultraviolet (UV) PPA and other PPA techniques.
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Low-Resolution or High-Resolution MS for Clinical and Forensic Toxicology: Some Considerations from Two Real CasesHow can low-resolution mass spectrometry (LRMS) and high-resolution (HR) MS work together to provide unambiguous results in clinical and forensic toxicology?
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Acid-Catalyzed Isomerization of Carbonyls-2,4- dinitrophenylhydrazone in Mainstream Smoke of Heat-Not-Burn Tobacco Product for HPLC AnalysisErrors arising from the DNPH approach commonly used to analyze carbonyl compounds in smoke from heat-not-burn (HNB) tobacco can be avoided by using the approach described in this study.
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Nonlinear Predictive Modelling Enables In Silico Optimization of Chromatographic Methods for Complex Stationary Phase‑Analyte InteractionsTo reach satisfactory results in terms of accurate retention time prediction, new in silico optimization approaches must be considered.
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Laser Desorption Postionization Mass SpectrometrySupplementing short pulse lasers with laser postionization increases ionization yields for desorption and ablation of solid samples in mass spectrometry. Here, we give an overview of the mechanisms and technical requirements for molecular photoionization in femtosecond (fs) laser desorption postionization mass spectrometry (LDPI-MS).
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Detecting Biomarkers in Breath using GC–MSBiomarker studies using exhaled breath are rapidly emerging as a technique for early disease detection and precision medicine. By offering a completely non-invasive experience for patients as an alternative to painful biopsy procedures. A new approach has the potential to enhance patient compliance, while making clinical workflows simpler. Exhaled breath analysis, however, requires a highly sensitive analytical technique capable of accurately measuring the broad range of volatiles present in breath. In this article, we present a proof-of-concept study to demonstrate a reliable and sensitive method to detect analytes in breath samples. Using high‑resolution accurate mass (HRAM) mass spectrometry (MS), the method validates how low- and high-abundance biomarkers can be quantified from exhaled breath.
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LCGC and ACS Subdivision on Chromatography and Separations Chemistry Survey 2023: What Skills Do New Analytical Chemistry Employees Need?For this year’s career issue, LCGC North America teamed up with the American Chemical Society Subdivision on Chromatography and Separations Chemistry to ask the analytical chemistry community what skills new employees in the field need to succeed. In this report, we analyze the survey results and explore how they can inform the future of analytical chemistry curriculum development.
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Fast HPLC Method Development Using Interfaced Photodiode-Array and Ion-Trap MS DetectionWith the goal of developing an analytical method for the fast analysis of vitamins in a complex matrix, the authors created a method that used in-line and complementary HPLC with photodiode-array and MS detection techniques.
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E-Mail and ChromatographyThis "Data File" column shows readers how to incorporate e-mail in chromatography data systems and suggests how other Internet technologies can improve modern laboratory practices.
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Ion Chromatography Using Anion Exchangers Modified with Anionic PolysaccharidesThe authors demonstrate a new detection method for various anions and cations separated by ion chromatography and point out the main advantages of this method.
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A Turnkey Protocol for Detecting Taste and Odor Compounds in Drinking and Surface Waters by Gas Chromatography–Mass Spectrometry and Electron Capture Detector (GC–MS/ECD)A comprehensive monitoring protocol has been developed using GC–MS/ECD in selective ion monitoring (SIM) mode, with injection performed by solid-phase microextraction (SPME) and headspace (HS). This single system has been configured to analyze for all taste and odor (T&O) compounds in Standard Method 2170, with minimal changing of columns, injectors, or SPME fibers between methods.
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IEC Analysis of Oligonucleotides and Evaluation of the Effect of Changes in Mobile Phase pH on SeparationAn analytical method for the separation of oligonucleotides of different chain length by IEC using a bio-inert UHPLC system is presented.
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Modifying the Metal Surfaces in HPLC Systems and Columns to Prevent Analyte Adsorption and Other Deleterious EffectsA novel surface modification technology has been developed to reduce interactions between analytes and metal surfaces in HPLC instruments and columns. We demonstrate the impact of this technology on peak symmetry, peak area, and injection-to-injection and column-to-column reproducibility for several metal-sensitive analytes.
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A Multiphase Sampling and Analytical Approach for Investigating Airborne PFAS TransmissionThe investigation of airborne PFAS transmission is important in preserving the outdoor urban environment. The authors explain why GC–MS/MS and LC–MS/MS are the best techniques for analyzing airborne PFAS.
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Rapid Simultaneous Determination of Five Major Alkaloids from Menispermi Rhizoma in Rat Urine by Ultrahigh-Pressure Liquid Chromatography– Tandem Mass Spectrometry (UHPLC–MS/MS) and its Application to a Urinary Excretion StudyA UHPLC–MS/MS method is described for rapid quantification of five major bioactive alkaloids in rat urine. The results obtained help lay the foundation for the clinical application and safety evaluation of the bioactive ingredients of menispermi rhizoma, used in herbal medicines.
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Innovation in Nutrition and Food Analysis: The FoodOmicsGR_Research InfrastructureFoodOmicsGR_RI aims to characterize unique Greek products and highlight their value and quality using cutting-edge omics technology.
