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A New High-Resolution, High-Speed Reversed-Phase Monolithic 1 mm I.D. Column for the Separation of ProteinsThe new reversed-phase ProSwift® 1 mm i.d. column is a divinylbenzene-based monolithic column for routine chromatography of proteins and other biomolecules. It is available in two different lengths. The shorter (1 Ã- 50 mm) format is designed for fast separations and the longer (1 Ã- 250 mm) format is intended for high resolution analytical separations. However, depending on the application, either can be used for separation of proteins and for coupling with mass spectrometry.
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Comprehensive Screening, Confirmation, and Quantification of Organic Pesticides in Foods by GC–MS and LC–MSWith the globalization of trade, food production and distribution have become truly international businesses. When we dine out, the fish might come from Japan, the rice from Australia, the spices from China, and the strawberries from Mexico. We take it for granted that the food we eat is safe and free from contamination that could make us seriously ill.
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Method 6040D, Odors in Drinking Water, Using SPME on the Supelco SLB-5ms Capillary ColumnA method for trace odor components, isopropyl-methoxypyrazine (IPMP), isobutyl-methoxypyrazine (IBMP), methylisoborneol (MIB), and geosmin in drinking water involving the use of solid phase microextraction (SPME) and the SLB-5ms capillary column using gas chromatography/mass spectrometry (GC–MS).
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Using Data Pretreatment to Improve ResolutionDid you know that applying the second derivative as a pretreatment to your near-infrared spectral data can help resolve overlapped peaks?
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GSH Conjugate Metabolite Identification with a Hybrid Triple- Quadrupole–Linear Ion-Trap Instrument and Automated Software-Driven Method DevelopmentIn drug discovery, determining information about the extent of metabolism and the elucidation of metabolite structures is a vital step for lead optimization and drug scaffold refinement. The identification and characterization of metabolites plays an important role in both the drug discovery and development phases, as unsuitable pharmacokinetics (bioavailability and drug distribution), toxicity, and adverse drug reactions might be linked to metabolic instability. Historically, metabolite identification was carried out after a compound had been chosen for drug development. However, to reduce candidate failures attributed to toxicity effects, many pharmaceutical companies now conduct these experiments in the earliest phases of candidate drug selection.
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Pesticide Analysis in Dietary Supplements Using Gas Chromatography Time-of-Flight Mass SpectrometryScreening for pesticide content is a common analysis that is done in laboratories where many samples need to be analyzed over a short period of time. The desire for a high-speed analysis is due to the need for a fast result from a potentially large volume of samples. A fast analysis is typically achieved through the use of high carrier gas flow rates in combination with temperature programming. A fast detector is needed in order to fully characterize the narrow chromatographic peaks generated from these experiments. TOFMS is ideal for detecting these narrow peaks because of its fast acquisition rate over a full mass range at all times during the experiment. In addition, TOFMS provides for non-skewed mass spectra making peak deconvolution possible.
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Extraction and Preconcentration of Residues and Contaminants in Food Samples Using Membrane TechniquesGuest authors from South Africa review the application of membranes in the extraction, preconcentration, and separation of various contaminants in food.
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Stability of Formic Acid in Methanol Solutions and the Implications for Use in LC–MS Gradient Elution AnalysisDilute formic acid solutions in methanol were found to decline in acid content with time, the extent of the decline depending upon the initial amount of water present in these solutions. The effect of the formic acid concentration change upon the separation of peptides using high performance liquid chromatography (HPLC) is examined briefly.
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Low and High pH Stability of an Agilent Poroshell HPHHPLC column stability is a critical factor. This note describes how the Agilent Poroshell HPH-C18 column performed brilliantly in an elevated pH mobile phases such as ammonium bicarbonate buffer.
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Analytical Methods to Characterize and Quantify PEG and PEGylated BiopharmaceuticalsBiotherapeutic peptides and proteins are often PEGylated (covalently bonded to polyethylene glycol polymers) to improve bioavailability, reduce immunogenicity, and extend circulating half-life (1). Achieving the desired properties for each application depends on optimizing the number and site of polymers attached, chain length, and the degree of chain branching.
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Atmospheric Pressure Photoionization — The Second Source for LC-MS?This article explores the progress that atmospheric pressure photoionization (APPI) has made in its relatively short history for LC–MS analysis. Specifically, the authors examine the combination of APPI and electrospray ionization (ESI).
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Bioinert Versus Biocompatible: The Benefits of Different Column Materials in Liquid Chromatography SeparationsIn this study, we compare the performance of plastic and metal materials in UHPLC columns designed for the analysis of biological molecules. We evaluate the performance of these materials in terms of inertness, column chromatographic performance, and reproducibility.
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GC–MS Screening for Melamine Adulteration in Baby Formula and Dairy ProductsMelamine is an industrial chemical with a high nitrogen content that can cause kidney stones and lead to renal failure. In some instances, melamine has been added to baby formula and dairy products as a substitute for protein. This paper presents an efficient and definitive gas chromatography–mass spectrometry (GC–MS) method to identify melamine and related compounds based on the released US Food and Drug Administration (FDA) method.
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Reproducibility of Retention Times and Peak Area in a UHPLC System (X-LC®)With recent advances in technology and the use of ultra high pressure chromatography systems becoming more commonplace, it is of use to compare reproducibility of retention time and peak area of UHPLC vs HPLC.
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The Misunderstood Laboratory Solvent: Reagent Water for HPLCA good pretreatment system combines reverse osmosis and electrodeionization technologies.
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msFineAnalysis AI for GC-AlphaThis application note provides an overview of JEOL’s innovative msFineAnalysis AI and its capabilities for enhancing GC-MS analysis.
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Reduced Solvent Usage and Increased Throughput for PAH Analysis Using UHPLCPolynuclear aromatic hydrocarbons (PAHs) are carcinogenic condensed ring aromatic compounds widely found as trace pollutants in waters, wastes, air particulates, soil and foods. PAHs can be routinely monitored using HPLC with a combination of UV and fluorescence detection as prescribed in EPA methods 550.1, 610 and 8310.
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Fast Gradient LC Using Your Existing InstrumentationTransforming "standard" gradient HPLC systems into extremely fast gradient systems is readily achievable with proper application of chromatographic principles, particularly temperature control, combined with utilization of advanced HPLC columns. Bottom line: You don't have to buy a new LC to achieve ultra high quality and speed!
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Rapid Separation of RhodaminesThis application note describes a rapid U-HPLC method for the separation of sulphorhodamine 101 (Texas Red®) and its three water-soluble derivatives using a Hypersil GOLD™ column packed with 1.9 μm particles.
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Automated Extraction Technique for Improved Recovery of PhenolsDionex has developed a new standard for flow-through solvent extraction which allows accelerated solvent extraction (ASE®) of matrices that have undergone acid or alkaline pretreatment or digestion. The new ASE 150 and ASE 350 systems use extraction cells and post-cell solvent pathways constructed of Dionium™ material. This pH-hardened substance resists corrosion under acidic or alkaline conditions used in standard pretreatments, widening the scope of ASE applications and significantly expanding its capabilities.
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IC–MS Analysis of Low Molecular Mass Organic Acids in BeveragesOrganic acids are present in many matrices and play crucial roles. Extensive research involving low molecular mass organic acids (LMMOA) has been performed in food chemistry since these acids contribute to the organoleptic properties of food and beverages, including flavor, color, aroma, taste, shelf-life, and health effects. Developing a profiling method to monitor LMMOA levels in raw materials and final products is very desirable. Many reported methods focus on limited numbers of LMMOAs and are incapable of providing a complete LMMOA profile.
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Analysis of Deoxynivalenol in BeerMycotoxins, toxic secondary metabolites of several fungal species, represent food safety issues of high concern. Deoxynivalenol, the most abundant trichothecene mycotoxin, can be found worldwide as a contaminant of wheat, barley, maize and other cereals (1,2). The transmission of deoxynivalenol from barley into beer has been reported in several studies (3,4). Therefore, its levels should be controlled.
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Development of a High-Throughput LC–MS Assay for Drugs of Abuse from Biological MatricesA high-throughput LC–MS method using core-shell UHPLC columns to screen for a panel of 11 drugs of abuse (expanded SAMHSA) was developed. The corresponding SPE method allowed the reproducible separation and quantitation of these 11 components in less than 2 min. This method demonstrates the power of new-generation HPLC media as well as some of the factors one must consider when developing such methods for LC–MS analysis.
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Quantifying Smoke Taint in California Wines by Immersive Sorbent Sheet Extraction Prior to Direct Analysis in Real-Time Mass Spectrometry (DART-MS)Measuring volatile phenols in wine is essential in ensuring superior wine quality. A new analytical technique, called solid-phase mesh-enhanced sorption from headspace (SPMESH), was modified with direct immersion (DI) conditions and coupled to direct analysis in real time–mass spectrometry (DART–MS) to be used to detect smoke taint in winemaking.
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Determination of Phenolic Compounds Using HPLC and Electrochemical Detection with Disposable Carbon ElectrodesPhenols are frequently present in water because of their widespread use in commercial products and because they are by-products of processes in petrochemical, pulp and paper, plastic, and glue manufacturing industries (1,2). The concentration of phenolic compounds in the waste discharges can be as high as 20 mg/L (2); however, phenol-containing pesticides and wood preservatives may cause significant health hazards even at mg/L levels (1). Consequently, it is important to monitor phenols and substituted phenols in environmental and biological samples. Liquid chromatography with electrochemical detection is one of the widely used methods due to its high selectivity and sensitivity for phenolic compounds. However, glassy carbon working electrodes, used in the electrochemical detection of phenols, often require polishing (3). This time-consuming and often poorly reproducible polishing can be avoided with disposable carbon electrodes, which offer comparable or better analytical performance (4).
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Inside the Personalized Medicine Toolbox: GCxGC-Mass Spectrometry for High-Throughput Profiling...The authors present results that suggest that high-throughput, high-coverage profiling capabilities, such as those afforded by GCxGC-TOF-MS, can impact the development of personalized medicine.
