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Screening 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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Guest authors from South Africa review the application of membranes in the extraction, preconcentration, and separation of various contaminants in food.

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Dilute 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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HPLC 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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Biotherapeutic 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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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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OI Analytical

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In 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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Melamine 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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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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A good pretreatment system combines reverse osmosis and electrodeionization technologies.

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This application note provides an overview of JEOL’s innovative msFineAnalysis AI and its capabilities for enhancing GC-MS analysis.

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Polynuclear 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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Transforming "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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This 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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Dionex 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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Organic 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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Mycotoxins, 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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A 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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Dionex Application note

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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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Phenols 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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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.

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The authors have developed a method of determining zeranol residues in bovine tissues without using toxic chemicals, organic solvents, and reagents in sample preparation and reversed-phase HPLC separation.

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Development of an ion chromatography (IC) method using suppressed conductivity detection for the determination of Cr(VI) in drinking water.

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Drug discovery scientists are continually striving to improve productivity and efficiency in their workflows. From early discovery to clinical development, existing workflow bottlenecks represent an opportunity to develop solutions to speed the process and improve productivity. The key requirements for quantitative analysis are precision, accuracy, and linear dynamic range. With any quantitative instrument, the hope is that it will be applicable to a vast range of coumpounds, ruggest, and fast. New mass spectrometry (MS) technologies are being developed that meet these criteria and permit high throughput while enabling its application to areas in which speed limitations previously curtailed its practicality. In particular, in the area of ADME profiling, new MS platforms are becoming available that increase the throughput by at least 25-fold, by combining the speed of matrix-assisted laser desorption ionization (MALDI) with the specificity of triple-quadrupole MS. This is bound to greatly accelerate the ADME..

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Escalating costs and increasing demands for helium, coupled with diminishing helium supply, have given rise to the investigation and use of hydrogen as an alternate choice of carrier gas for use in gas chromatography (GC) applications. This application note illustrates that the use of hydrogen as a carrier gas as an alternative to helium in refinery gas applications is not only possible, but also results in improved performance and higher sample throughput.

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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.

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In 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.