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Reversed-Phase Enantioselective Chromatography with New µ-mm Chiral Stationary PhasesTo meet the growing need for fast reversed-phase enantiomer separations, two new 3-μm reversed-phase columns, CHIRALCEL® OD® -3R and CHIRALPAK® AD® -3R, have been introduced. High column performance and column stability under a wide range of conditions, including aqueous solvent systems suited to LC–MS, have been
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Use of Electron Capture Negative Ion Mass Spectra to Establish the Identities of Polybrominated Diphenyl Ether Flame Retardants and Their Degradation ProductsDetrimental health effects of a group of brominated flame retardants, polybrominated diphenyl ethers (PBDEs), have been recognized recently, but only after their wide usage and consequently, global dispersal. Of the possible 209 PBDE congeners, 39 (varying in degree of bromination from mono to deca) have been identified previously in the three common technical mixtures. Additional congeners, presumably debromination products of the fully brominated decabromodiphenyl ether (BDE-209), also have been reported in biotic and abiotic environments. However, costly analytical standards are needed to confirm their identification. In addition, the most widely used identification approach, electron ionization (EI) mass spectrometry (MS), primarily produces spectra indicating only homologue grouping (for example, hepta-BDE). Without specific compound identification, full assessment of toxicological consequences of PBDE burdens is impeded. It has been reported previously that electron-capture negative ionization (ECNI),..
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Approaches to Singleton Achiral Purification of Difficult Samples for Discovery Research SupportSeveral approaches for purifying difficult samples more efficiently for discovery research support are mentioned in this paper. These approaches use mass triggered HPLC on various specialty columns.
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Detection of Doping Agents by LC–MS and LC–MS-MSIn the last decade, research on the detection of all groups of doping agents has been investigated by LC-MS, and routine LC-MS screening applications are now available for almost all classes of doping agents.
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Dynamic Extraction: A High-Speed, High-Capacity Purification Process That is Rapidly ScalableThe authors discuss a preparative process using the principles of countercurrent chromatography. This process is faster, capable of loadings from milligrams to hundreds of grams, and uses robust equipment.
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Simultaneous Measurement of an API with its Counter-ion Using Corona CAD with HPLC-HILICThe analysis of anions and cations is critical during drug development and related QC. Measure both the API and the counterion in a single run.
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Determination and Quantification of Primary Aromatic Amine in Printer InkKnauer Application Note
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Ion Suppression: A Major Concern in Mass SpectrometryIn this tutorial, the mechanism and origin of ion suppression will be investigated, as well as ways to validate the presence, and circumvent or compensate for, the effects in LC-MS.
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Agilent J&W Ultra Inert GC Columns: A New Tool to Battle Challenging Active AnalytesQC test probes serve a vital function in ensuring the reproducibility of modern GC columns. These probes ensure that the columns have been properly deactivated, contain the correct amount of stationary phase, and have the same relative retention as the last column purchased. The choice of individual compounds in these test mixes varies widely and can have profound consequences on the performance of a column in the users' applications.
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The Use of Subtle Differences in Selectivity to Improve Separation of Structurally Diverse AnalytesThe separation of structurally diverse analytes is often complicated by chance coelutions with other analytes or with matrix related compounds. Often the column is blamed, but while such coelutions make analysis difficult they do not necessarily indicate a faulty column, poor chromatography or method design.
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Approaches to Singleton Achiral Purification of Difficult Samples for Discovery Research SupportSeveral approaches for purifying difficult samples more efficiently for discovery research support are mentioned in this paper. These approaches use mass triggered HPLC on various specialty columns.
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CAPCELL PAK C18 MG III, Polymer-coated C18 Stationary Phase, Designed for High-Sensitivity analyses in LC–MSThe SHISEIDO CAPCELL PAK C18 MGIII is an HPLC column packed with a silicone polymer-coated phase, providing excellent peak profiles for basic compounds under acidic conditions, and generating ultimately minimized column bleeding in LC–MS.
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Sulfated β-Cyclodextrin as Chiral Mobile Phase Additive for Ultrahigh-Pressure Liquid ChromatographyA fast enantiomeric separation of a chiral aromatic amine was achieved, using ultra high pressure liquid chromatography and highly sulfated β-cyclodextrin (S-β-CD) as a chiral additive in the mobile phase. The stationary phase consisted of a core shell support with a particle size of 2.7 µm. Under these conditions the baseline separation was obtained within 2.5 min. The influence of the concentration of the additive, along with the thermodynamics of the separation, were studied. Molecular mechanics calculations were consistent with the experimental data for the order of elution, providing further evidence of these interactions. The enantiomeric separation at high temperature (90 °C) using only water as mobile phase also was achieved for the first time.
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Determination of Volatile Organic Compounds in Water by In-Tube Extraction and Gas Chromatography with Ion-Trap Mass SpectrometryOver the last 10 years, several solvent-free microextraction techniques for gas chromatography (GC) and mass spectrometry (MS) have been developed. Two of these techniques, solid-phase microextraction (SPME) and stir-bar sorptive extraction (SBSE), are available commercially for the analysis of volatile compounds, such as flavors in foods and beverages, and toxic organic compounds in environmental applications. Other techniques, such as open tubular trapping, inside needle capillary adsorption trap (1), in-tube SPME, capillary microextraction, needle trap, and headspace solid-phase dynamic extraction (2), were also developed for different applications. The basic principle for all of these techniques is essentially the same. Volatile and semivolatile compounds are adsorbed on a sorbent coating, often packed on the interior surface of a capillary column or stainless steel needle. After the sample is concentrated on the coating, the compounds are desorbed thermally in the heated injection port of a gas..
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Fast Multi-Residue Pesticide Analysis Using Triple Quadrupole GC–MS-MSH-SRM provides excellent selectivity for accurate identification and quantification of pesticides in matrix, demonstrating high productivity for effective control at international maximum residue levels (MRLs).
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Analysis of Hydrophilic Molecules in Biological Fluid with Novel Mixed-Mode ColumnIn pharmaceutical development, it is important to analyze small molecules or their metabolites in biological fluids. For this purpose, the analytical methods such as sample pretreatment, 2D-LC and LC–MS have been developed. However there are still problems of resolution and protein adsorption. As a result, satisfying analytical results have not always been achieved.
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Comparing Scientific Marketing to Analytical RealityConsumer marketing approaches are creeping into the marketing of scientific instruments. With a careful approach, you can cut through the hype.
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Use of Orthogonal Methods During Pharmaceutical Development: Case StudiesThe primary goal of early phase development is to gain a fundamental knowledge of the chemistry of drug substances and drug products to facilitate optimization of synthetic schemes and drug product formulations. At the same time, methods are required for release and stability studies to support clinical trials. Ultimately, the knowledge gained during early development translates into designing control methods for commercial supplies. Our approach to meeting this challenge is based upon the use of a primary method along with orthogonal methods. This paper will discuss the overall strategy, with an emphasis on the chromatographic conditions selected to provide systematic othogonality for a broad range of drugs. Case studies will be presented to demonstrate the utility of orthogonal methods to resolve issues that could not have been addressed using a single release and stability method.
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Quantitative Comparison of Hormones in Drinking Water Between Low and High Resolution Mass SpectrometryThe quantitative performance of the latest generation of high-resolution instruments is comparable to that of a triple quadrupole MS, even though different scanning modes are used. Higher-resolution instrumentation also allows flexibility concerning compound identification because the experiment can be set up for targeted quantitation, screening, or both. In an Orbitrap-based instrument, the parallel reaction monitoring (PRM) mode performs most closely to a triple quadrupole mass analyzer using selected reaction monitoring (SRM) mode. This study looks at the performance of an Orbitrap-based LC–MS method for EPA Method 539.
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A Quality-by-Design Methodology for Rapid LC Method Development, Part IIIThe guest columnists continue their examination of how statistically rigorous QbD principles can be put into practice.
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Get More Separation Power With Multidimensional ChromatographyMultidimensional chromatography, or comprehensive chromatography, is a well-established technique for the analysis of complex mixtures. However, the technique is often perceived as highly complex and difficult to put into practice for routine applications. Nonetheless, the technique provides exceptional potential for addressing challenging separations. The addition of a dilution factor allows multidimensional chromatography to provide a high level of flexibility and selectivity. The dilution effect is achieved by using a column chemistry format compatible with large flow rates, which now offers the option of large volume injection without volume or mass overload issues. This novel solution can reduce or eliminate the need to add a solvent exchange step, such as evaporation or reconstitution, which significantly reduces the most time-consuming part of the sample preparation process.
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Evaluation of Extraction Methods and Bias Correction by EPA Method 6800 Protocol for Mercury Species in Tuna Fish Tissue Using an Ion Chromatograph Coupled to an ICP–MSMercury pollution mainly originates from industrial activities such as chlorine production, garbage incineration and above all coal-fueled power generation. The US Environmental Protection Agency (US EPA) considers mercury as highly toxic with a pronounced accumulative and persistent character.
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Chemical Warfare Agent Spectral Imaging for Real-Time Identification and LocalizationIn this article, the authors discuss the need for protection against chemical attacks and the role of passive imaging spectroradiometers in the detection of remote chemical agents.
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Extraction and Detection of Antibiotics in the Rhizosphere MetabolomeRoot diseases caused by soilborne plant pathogens are responsible for billions of dollars of losses annually in food, fiber, ornamental, and biofuel crops. The use of pesticides often is not an option to control plant diseases because of economic factors or potential adverse effects on the environment or human health. For this reason, many Americans are now buying pesticide-free organic foods. Organic agriculture has few options for controlling pests and thus must make full use of natural microbial biological control agents in soils that suppress diseases.
