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Chromatographic Isolation of Sensitive Compounds: Challenges and SolutionsIn this installment of “LC Troubleshooting,” we discuss strategies that can be used to minimize the likelihood of compound degradation in the isolation process.
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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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PFAS in Air Analysis by TD–GC–MSAnalysis of trace per- and polyfluorinated organic vapours in air using cryogen-free thermal desorption and gas chromatography–mass spectrometry.
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Passing the Test: Understanding Proficiency TestingLaboratories use proficiency tests (PTs) to comply with their accreditation requirements and evaluate analysts’ performance. Laboratories regard PTs as a burdensome chore that must be successfully completed to satisfy internal or external compliance or accreditation requirements. PTs are an integral part of a quality management system (QMS) under quality assurance and control (QA/AC). Understanding the core components of the QMS is an important part of passing any PT test. Unacceptable PT results may have little to do with the result itself but reflect the use and application of statistics, standards, and methods.
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Micro-Pillar Array Column Separations for Proteomics of Liver OrganoidsA micro-pillar array format for mapping the proteome of human stem cell-derived liver organoids using timsTOF–MS is presented.
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Determination and Validation of a Single Laboratory Method for Coenzyme Q10 (Ubiquinone) by UHPLCA fast ultrahigh-pressure liquid chromatography (UHPLC) method, with low solvent consumption, is described for the determination of coenzyme Q10 in a variety of complex formulations. This method exhibits good linearity, reproducibility, accuracy, recovery, and specificity, while resulting in an acceptable limit of detection (LOD) and limit of quantification (LOQ).
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Analysis of Microplastics in Roadside Debris by Py-GC-MS (Sept 2024)Tire wear particles left on roads can cause marine and air pollution. Py-GC-MS identifies and quantifies microplastics present in air, sand, soil, and other materials.
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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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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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Columns - What is on Your HPLC Particle? A Look at Stationary Phase Chemistry SynthesisThis article reviews historical bonding techniques still in use for manufacturing high performance liquid chromatography (HPLC) stationary phases today, and also examines some emerging technologies that may be able to tackle unmet needs in novel platforms and phase construction.
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Harmonization of Experimental Methods Used to Measure the True Hold-Up Volume of Liquid Chromatography ColumnsA harmonization of all conventional hold-up volume methods was successfully applied to RPLC, HILIC, AEX, and RP-AEX mixed-mode chromatography, regardless of the mobile phase.
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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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Indirect Suppressed-Conductivity Ion ChromatographyThe authors demonstrate a new detection method for various anions of weak acids separated by ion chromatography and point out the main advantages of this method.
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Development of a “Freeze-Pour” Sample Preparation Method for the GC Analysis of Semivolatile Flavouring Chemicals Present in E-cigarette Refill LiquidsHS-GC analysis is presented as an excellent method for the analysis of high volatile components in e-liquids. For the analysis of semivolatile ingredients, an additional sample preparation step is proposed based on a LLE followed by a freeze-out of the matrix components.
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Coupling Static Headspace Sampling to High-Speed Gas ChromatographyRoutine analysis of volatiles from fruit juices can be sampled and concentrated using a static headspace method and rapidly analyzed by high-speed GC.
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Supercritical Fluid Chromatography for Chiral Analysis, Part 2: ApplicationsIn the second part of this review article, the recent progress in SFC for enantiomeric separations is evaluated. Several applications reported on the enantioselective separation of drugs and pharmaceutical compounds using chiral SFC are discussed, including pharmaceutical applications, clinical research, forensic toxicology, and environmental sciences.
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Investigating Decomposition Odor in a Tropical Climate by Comprehensive Two-Dimensional Gas Chromatography (GC×GC) Coupled with Mass Spectrometry (MS) and Flame Ionization Detection (FID)Decomposing animal tissue releases volatile organic compounds (VOCs), of interest in forensic science. We describe the use of GC×GC–qMS/FID retrofitted with a reverse fill/flush (RFF) flow modulator for analyzing these VOCs in a tropical climate.
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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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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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Tools for Investigating the Expanding Per- and Polyfluoroalkyl Substances (PFAS) UniverseWith suspect PFAS screening becoming more popular, and the list of known PFAS now in the thousands, novel analytical tools are needed to generate transferable data sets. We highlight key updates here.
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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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The LCGC Blog: Chromatographers and Chromatography UsersAre you a chromatographer or a chromatography user?
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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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Analysis of Near 400 Pesticides in Tea via LC–MS/MS: Simple Sample Preparation and APCI to Improve Analyte CoverageThis method greatly facilitates the analysis of a large number of pesticides.
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Monitoring for Per- and Poly-Fluoroalkyl (PFAS) with Advanced Mass Spectrometry– Based MethodsPer- and poly-fluoroalkyl substances (PFAS) are a family of potentially thousands of synthetic compounds that have long been used in the manufacture of a variety of common products with stain-repellent and nonstick properties. Their signature strong fluorine and carbon bonds make them difficult to break down and, as a result, they are among the most persistent of today’s environmental pollutants. Alarmingly, PFAS can be found in drinking water and have been shown to accumulate in the body with the potential to cause multiple health problems, such as hormone disruption and cancer. Advances in mass spectrometry have facilitated the detection of known PFAS contaminants as well as the identification of poorly studied and novel compounds in watersheds. This article explores the detection of known and novel PFAS contaminants in aqueous film-forming foams and raw drinking water sources in North Carolina, using new advances in mass spectrometry and data acquisition to improve identification and quantitation.
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Fast and Efficient Volatile Compound Analysis by Purge-and-Trap GC-MSThe author configured a purge-and-trap GC-MS system that simultaneously improved chromatographic resolution and reduced analysis time.
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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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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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Separation and Characterization of Macromolecules: SCM-11 PreviewSeparation and Characterization of Macromolecules 11 (SCM-11) will take place from 22–24 January 2025 in Amsterdam, The Netherlands.
