Application Notes: General

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LEAP has developed a new instrument for collecting the entire mobile phase stream during metabolic profiling HPLC–MS analyses into a sealed, 96-well, LTuma plate.

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Explosive compounds are widely used in warfare, mining industries, terrorist attacks, and civil constructions. Explosive contaminated soils are mostly found on firing points, impact areas, and training ranges. The explosive contaminates in soil are possible sources for surface and ground water contaminations, posing environmental and public health risks due to the compounds' toxicity, carcinogenicity, and mutagenicity.

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For many years, the use of guard columns has been advocated by column manufacturers and other experts to protect and extend column lifetime and performance of analytical columns from potential damage caused by the presence of chemical contaminants and microparticulates in the sample and mobile phase.

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One of the most important attributes of flexible fused silica capillary tubing is its outstanding strength. When made properly with a protective abrasion resistant coating and handled appropriately this material has proven to maintain its strength remarkably well.

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Ionic Liquids by IC–MS

The characteristic composition of ionic liquids (an organic cation or anion and a counterion, in either organic or inorganic form) exhibits unique properties, such as extremely low vapor pressure, excellent thermal stability, electrical conductivity, high polarity, and miscibility with various types of solvents.

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Cyanide, an environmental contaminant, can cause serious health effects including goiters, hypothyroidism and some neuromuscular diseases. Cyanide wastewater sources include the plating and mining industries, burning of coal and plastics and effluent from publicly owned treatment works (POTW).

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The term ionic liquid refers to organic salts with relatively low melting points (below 100 °C) that usually consist of an organic cation or anion and a counterion, in either organic or inorganic form. Ionic liquids exhibit unique characteristics such as extremely low vapour pressure, excellent thermal stability, electrical conductivity, a high degree of polarity and miscibility with various types of solvents. Ionic liquids have been used as catalysts and solvents in organic chemistry and electrochemistry and as mobile phase modifiers or functionalized stationary phases in separation science.1–3

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The free and total content of detrimental glycerol in vegetable oil methyl esters (biodiesel) is of paramount importance for the quality of biodiesel and is, therefore, limited by the US ASTM D 6751 and the European EN 14214 standards. Both regulations currently stipulate gas chromatographic (GC) analysis of free and total glycerol. However, the GC method, apart from being expensive, requires tedious derivatizations and fails for glycerol determinations in coconut or palm kernel oil methyl esters.

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As UPLC users convert or replace their existing HPLC systems with UPLC systems there is a transition period where a method must be run on both platforms. Thus, having the same particle substrate and bonded phases available in HPLC and UPLC particle sizes can significantly ease the burden of method development and transfer from one platform to another. In addition to the ethylene bridged hybrid (BEH) particle, three new high strength silica (HSS) stationary phases for HPLC applications are introduced. Scalability between both column diameter and particle size is demonstrated on both UPLC and HPLC instrumentation.

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According to the FDA policy statement, developing stereoisomeric drugs, each enantiomer should be evaluated.1 As a result, the pharmaceutical industry has escalated its emphasis on the generation of enantiomerically pure compounds before undertaking pharmacokinetic, metabolic, physiological and toxicological evaluations.2 Chiral chromatography, especially SFC, is the most widely used technique for obtaining mg to multigrams of pure enantiomers in drug discovery. In SFC, a combination of supercritical CO2 and polar organic solvent(s), most commonly alcohol, are used as the mobile phase. Because of the higher diffusivity and lower viscosity of supercritical fluid, SFC often provides a 3–8-fold faster separation than normal-phase HPLC. For chiral purification, SFC also offers significant cost savings by reducing organic solvent usage and removal as well as the time and energy required post-purification. As SFC instrumentation continues to improve, SFC has gradually overtaken HPLC as the first choice..

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This application note describes a rapid UHPLC method for the separation of Sulforhodamine 101 (Texas Red®) and its three water-soluble derivatives using a column packed with Thermo Scientific Hypersil GOLD™ 1.9 μm particles.

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BPA or bisphenol A has become well know over the past year as concerns for its effect on human health and well being have been raised. The concerns over BPA in plastics began with baby bottles and spread to include other types of bottles and toys.

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The analysis of the molar mass distribution of polyethylene and polypropylene resins by GPC/SEC has always been considered a demanding task because of the requirement of high temperature operation for dissolution and complex hardware design, which often results in high maintenance cost, in particular related to the autosampler/injector and detector units, and in other problematic and consuming tasks such as solvent handling added to column fragility, sample degradation, or detector sensitivity–stability.