Recent Articles in Separation science - Articles and Application notes
Dionex Beverage Application Notebook Demonstrates Unique Analytical Solutions for Commonly Used BeveragesMar 17, 2010
The Dionex Beverage Application Notebook, a compilation of beverage applications in an easy-to-use PDF, is available on the Dionex website at www.dionex.com. The global beverage industry is growing each year with the introduction of new products, such as vitamin-fortified water, energy drinks, anti-aging water, and herbal nutritional supplements.
Read MoreInformative Report on Deep Well Microplate SampleFeb 18, 2010
A new technical report is available from Porvair Sciences Ltd. that investigates and demonstrates the importance of high quality raw material selection for the manufacture of deep well microplates.
Read MoreMelamine Contamination Resurfaces in China!Feb 9, 2010
The 2008 China melamine scandal in which the discovery of milk powder adulterated with melamine led to a global recall of Chinese infant milk formula, chocolates, biscuits, cakes, and other milk-based products is resurfacing. This month, the China Daily reports that melamine-contaminated milk-based products from three companies have been removed from shelves in the Guizhou province.
Read MoreDionex Applications for Securing Purity of Anti-Coagulant HeparinJan 15, 2010
Dionex Corp. is pleased to announce the availability of two application notes created in support of the official release of the United States Pharmacopeia (USP) stage 2 heparin sodium monograph, published October 1, 2009
Read MoreThe Bio-ChromatographersDec 30, 2009
Simply high dynamic binding capacities (DBC’s) are no longer sufficient. High DBC, at high flow rates with close to 100% recovery, across a wide range of molecular weights, this is what chromatographers look for in modern ion exchange resins. “BioPro” YMC’s hugely successful ion exchange material offers exactly this. The growing user base confirms very good separation, high dynamic binding capacities and excellent recoveries for the anion as well as the cation exchanger material.
Read MorePreheating of mobile phases - "nice-to-have" or "need-to-have"?Dec 30, 2009
Controlling the temperature of a column is a prerequisite for reproducible results in HPLC. Column ovens are part of most HPLC systems and many of them offer space even for semi preparative columns. But with increasing inner diameter the heat transfer from the air surrounding the column to the whole cross section of the column (filled with the cold mobile phase) becomes more and more difficult. This may result in bad peak shapes, as the radial temperature gradientcauses different separation conditions for every part of the sample depending on its distance to the outer diameter.
Read MoreHPLC-Tip: Degassing of the mobile phaseDec 30, 2009
A released gas in mobile phases during analysis causes noisy baselines and pressure fluctuations which affect sensitivity and reproducibility. It also severely compromises the use of fluorescence-, refractive-index- or UV-detectors (particularly at wavelengths below 210 nm). As a consequence effective mobile phase degassing must be employed for many analyses.
Read MoreUltra Fast LC for Peptide mappingDec 29, 2009
In order to succeed in developing protein-based drugs, a fast and easy detection of alteration within the protein structure is necessary. In many cases, peptide mapping is the method of choice, where proteins are analysed after digestion.
Read MoreFast routine analysis of alkaloidsDec 29, 2009
The method transfer from a conventional column to an ultra fast analysis for alkaloids has shown that the use of YMC-UltraHT 2 µm column and adjustment of flow parameters for the smaller column dimensions can reduce the analyses time by about 85% accompany with significant solvent savings and significant solvent savings whilst increasing the sample throughput in the laboratory.
Read MoreHPLC hint: The advantage of premixed solvents in HPLCDec 29, 2009
For several reasons the storage of 100% pure solvents in the reservoir bottles of an HPLC system can be a problem. Pure acetonitrile, in particular, affects the system by adsorption of polymers from transmission lines resulting in sticky surfaces that inhibit the opening and closing of the valves
Read MoreSimultaneous separation of pesticides by LC/MSDec 29, 2009
With the constantly rising population and frequent uncertain weather, the need for high yielding agriculture is paramount. This means that use of plant protection agents, such as herbicides and insecticides is necessary, in order to secure harvests.
Read MoreNormal Phase Chromatography Dec 28, 2009
Normal phase chromatography is not very popular with most analytical HPLC users. Poor reproducebility of the results is often cited as an argument against normal phase chromatography.
Read MoreFastLC Application for CurcuminDec 28, 2009
The plant pigment curcumin, found in the popular Indian curry spice turmeric, is well known as an antioxidant for foods. However, researches have paid attention to another characteristic. Curcumin is highly active against the growth of certain cancers.
Read MoreMelamine in pet-foodDec 23, 2009
Melamine (sometimes confused with the plant and animal compound, melanine or another compound, melanin) is an industrial chemical used in the manufacture of plastic products. Despite that, tests showed that a number of milk companies have used it in processing milk to artificially increase the apparent protein content by addition of non-protein nitrogen and so allowing illegal dilution of the product with water with a corresponding increase in sales value.
Read MoreDetection of Mycotoxins in NutsDec 21, 2009
Mykotoxins are natural metabolism products of molds which have a toxic effect on humans and animals. Just like micro-organisms which generate antibiotics, molds which generate mycotoxins have spread all over the world. Aflatoxins are the most toxic form of mycotoxins. Some types of food show an increased risk of aflatoxin release due to fungal infestation: dried fruit, spices, nuts (peanuts, hazelnuts, pistachios) and grain (wheat, corn).
Read MoreMycotoxins in NutsDec 11, 2009
Every year during the pre- holiday activities the use of nuts increases in order to prepare for the holiday baking. To a large degree unnoticed by consumers is the problem of a possible contamination of these foods with mycotoxins.
Read MoreDionex Application Demonstrates a More Efficient and Precise Determination of Steviol Glycosides in Consumer SweetenersDec 11, 2009
Dionex announces a new method for determination of steviol glycosides in consumer sweeteners, which is precise, accurate, and more efficient compared to existing methods (USP and JECFA monographs).
Read MoreTrace-level aliphatic amines in pharmaceutical ingredientsNov 6, 2009
The determination of aliphatic amines in interfering matrices is a challenging task because protonated amines are often poorly retained on the column. This problem is met by applying ion chromatography using coupled-column matrix elimination.
Read MoreIon chromatographic analysis of carbohydrates in essential and non-essential foodstuffsNov 5, 2009
This article describes a straightforward ion chromatographic method that uses isocratic elution and pulsed amperometric detection (PAD) to sensitively determine water-soluble polyols and sugar alcohols as well as mono-, di- and oligosaccharides in essential and non-essential foodstuffs. While carbohydrate determination of most foodstuffs requires only minimal sample pretreatment such as dilution and filtration, samples with interfering matrices such as protein-containing dairy products have to be dialyzed prior to injection.
Read MoreMono Trap A New Generation Tool Adsorption & ExtractionOct 30, 2009
MonoTrapTM is a state-of-the-art silica monolithic and hybrid adsorbent having a large surface area and properties based on silica, activated carbon and Octadecyl functional group.
MonoTrapTM can be used for the simple enrichment analyses and screening of aroma components, foods and environment
This article provides examples of how to collect samples and extract solvents using the MonoTrapTM and provides the information needed to accomplish these tasks with expertise.
Based on Monolithic technologies, Merck KGaA, Darmstadt, Germany
Read MoreMonoTrap Handling Instructions (Version 1-0)Oct 8, 2009
MonoTrap™ is a silica-based adsorptive. This product can be characterized by through pore (due to the monolith structure of the silica base) and a large surface (due to the pores within the silica frame). Active carbon is used as an adsorptive on the silica frame surface to which octadecyl (ODS) group has been conjugated.
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