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Stability and Recovery Influences of Benzo[a]pyrene, Benzo[a]anthracene, Benzo[b]fluoranthene, and Chrysene during Sample Preparation of Plant MatricesQuantification of European Union (EU)-priority polycyclic aromatic hydrocarbons (PAHs) in plant matrices is a crucial task. Various methods for enrichment and preconcentration, such as the preloaded-pipette tip solid‑phase extraction (SPE) (1), are available. Nevertheless, analyte recovery as a result of homogenization, sample preparation, and extraction are rarely discussed in the field of phytopharmacy. This study deals with the recovery in dry plant extracts, which are typically used in phytopharmaceuticals and reflect the actual polycyclic aromatic hydrocarbon content in the commercially available end product (2). The aim of this study was to monitor benzo[a]pyrene, benzo[a]anthracene, chrysene, and benzo[b]fluoranthene loss of spiked samples as a result of commonly-used sample pretreatment, extraction, filtering, and evaporating techniques in 1:1 (v/v) cyclohexane–ethyl acetate primulae flos and sambuci flos dry extracts. Results showed that improper sample preparation can lead to false results. In the case of benzo[a]pyrene with a deviation of 155% from the theoretical true value.
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Exploring the Implementation of Compact Chromatographic Instrumentation in Common Analytical WorkflowsCompact instrumentation offers important advantages for many workflows, as illustrated by these examples.
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Biomimetic HPLC Methods for Drug DiscoveryModified nucleosides, either natural or synthetic, often provide RNA with distinctive properties useful in diagnostics or therapeutics.
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Analytical Advantages of Highly Stable Stationary Phases for Reversed-Phase LCDuring the past five years, many manufacturers of HPLC columns have focused on improving stationary phase stability and reproducibility. In this study, the authors use a variety of test solutes to compare the efficiency, selectivity, and hydrophobic retention mechanisms of five commercially available HPLC columns based silica, alumina, zirconia, and polystyrene cross-linked with divinylbenzene as the support.
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The 15th Multidimensional Chromatography WorkshopThe 15th Multidimensional Chromatography Workshop is a free event involving keynote and contributed presentations, a poster session, and discussion groups on all multidimensional techniques, and will be held in-person on the campus of California State University, Los Angeles, from January 10 to 12, 2024.
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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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Effect of Mobile Phase pH and Counterion Concentration on Retention and Selectivity for a Diol Column in Hydrophilic Interaction Liquid ChromatographyThis work focuses on the effects of the mobile phase pH and the counterion concentration in buffer solution on retention in hydrophilic interaction liquid chromatography (HILIC) mode.
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Improving Selectivity in the Chromatographic Analysis of Monoclonal Antibodies (mAbs) Through the Use of Multi-Isocratic Elution ModeMulti-isocratic elution mode is a powerful chromatographic approach for characterizing minor isoforms of monoclonal antibodies.
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Application of Porous Layer Open Tubular Columns: Beyond Permanent GasesThe application of porous layer open tubular (PLOT) columns can be expanded beyond light compounds to separations of analytes with heavier boiling points.
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Determination of Microplastic Mass Content by Thermal Extraction Desorption Gas Chromatography–Mass SpectrometryA novel analysis technique has been developed for the determination of microplastics (MPs) in complex environmental samples using thermal extraction desorption gas chromatography–mass spectrometry (TED-GC–MS).
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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 Flash Qualitative Identification Method for the Specific Component in a Mixture Based on Diode Array DetectorThis paper proposes a new method of flash qualitative identification (FQI) to qualitatively identify a certain target component from a mixture within half a second by disusing the analytical column, which is a time-consuming unit in current chromatography instruments. First, a Noised Spectrum Identification (NSI) model was constructed for the data set generated directly by diode array detector (DAD) without the process in an analytical column. Then, a method called vector error algorithm (VEA) was proposed to generate an error according to the DAD data set for a mixture and a specific spectrum for the target component to be identified. A criterion based on the error generated by the VEA is used to give a judgement of whether the specific spectrum exists in the DAD data set. Several simulations demonstrate the high performance of the FQI method, and an experiment for three known materials was carried out to validate the effectiveness of this method. The results show that the NSI model concurs with the real experiment result; therefore, the error generated by the VEA was an effective criterion to identify a specific component qualitatively, and the FQI method could finish the identification task within half a second.
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Solutions for Oligonucleotide AnalysisThis overview of instruments and applications shows various solutions for purification, characterization and quality control which are indispensable for the development of oligonucleotide therapeutics.
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Possibilities and Limitations of Aqueous Temperature Responsive Liquid Chromatography in Comprehensive 2D–LCAnalyzing representative standard mixtures, APIs, and synthetic impurities shows that when TRLC is combined with RPLC in 2D-LC, separation performance is improved. We explain why.
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Electromembrane Extraction with Vials of Conducting PolymerIn electromembrane extraction (EME), the target analyte is extracted from an aqueous sample across a supported liquid membrane (SLM) and analyzed using LC. Through the study presented here, we demonstrate the principles of the technique and test its performance.
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When van Deemter Goes Upside Down in Chiral ChromatographyThe occurrence of convex-upward van Deemter curves is rare but not unusual in chiral liquid chromatography. In this work, this behaviour, experimentally observed for the more retained enantiomer of a chiral sulfoxide on a polysaccharide-based CSP, is explained.
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In Memory of Pavel Jandera, Leading ChromatographerProfessor Pavel Jandera passed away suddenly and unexpectedly on August 5, 2021. He was one of the most famous Czech analytical chemists. He was 77 years old.
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Optimization of Determination Method of Cooling Agents in Cigarette Tipping Paper by Gas ChromatographyThis GC–FID method enables accurate determination of cooling agents, which are flavor compounds commonly used in cigarette tipping paper.
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Separation of Semaglutide and Liraglutide on NanoPak-C All Carbon HPLC columnsThis note summarizes the optimal methods for the HPLC separation of semaglutide and liraglutide under acidic and alkaline conditions.
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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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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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Achieving Optimum GC Separation – Designing New Capillary Column Stationary Phases Using Computer ModelingBy calculating optimal stationary-phase composition and physical parameters, column developers can construct columns that provide the exact separation requirements desired by analysis or current methods.
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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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Measuring Stress and Reproductive Hormones in Dolphins with UHPLCA recent study measured stress and reproductive hormones in three stocks of free-ranging bottlenose dolphins inhabiting different natural salinities across the Gulf of Mexico, with hormones extracted from the blubber of 82 remotely biopsied dolphins and quantified using ultrahigh-pressure liquid chromatography (UHPLC) coupled with orbital ion trap fusion mass spectrometry.
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Analysis of omega-3 supplements by GC-FID (Oct 2023)FAME and cis/trans FAME composition of three omega-3 supplements have been analyzed using two different columns, a 100% polyethylene glycol and a 100% biscyanopropyl.
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Insights into the Shape-Selective Retention Properties of Porous Graphitic Carbon Stationary Phases and Applicability for Polar CompoundsWhen the unique shape-selective properties of PGC are appropriately identified, PGC stationary phases can be harnessed for fine separations of structurally related compounds.
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Technical Note: Modifying a Standard HPLC Autosampler for On-Line Process MonitoringA simple modification of the standard HPLC autosampler flow path enables automated sampling and analysis of samples outside the autosampler unit when users cannot place the sample container inside because of size restrictions.
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Possibilities and Limitations of Aqueous Temperature Responsive Liquid Chromatography in Comprehensive 2D–LCAnalyzing representative standard mixtures, APIs, and synthetic impurities shows that when TRLC is combined with RPLC in 2D-LC, separation performance is improved. We explain why.
