Anion-chromatographic technique

Kieber et al. [12] determined formate in non saline waters by a coupled enzymatic/high performance liquid chromatographic techinique. The precision is approximately 5% relative standard deviation. Inter-calibration with an anion chromatographic technique showed an agreement of 98%. Down to 0.5pmol L 1 absolute of formate could be determined. Kieber et al. [12] found 0.2-0.8mol IT1 formate in seawater and 0.4-10pmol in rainwater. 

Various chromatographic techniques may be utilized to purify urokinase further. Commonly employed methods include anion-exchange (DEAE-based) chromatography, gel filtration on Sephadex G-100 and chromatography on hydroxyapatite columns. Urokinase is a relatively stable molecule. It remains active subsequent to incubation at 60 °C for several hours, or brief incubation at pHs as low as 1.0 or as high as 10.0. 

The separation mechanism is quite different from other chromatographic techniques and a broader spectrum of possible impurities can be detected at the same system (e.g., inorganic small cations, anions by indirect detection, chiral separations by adding a chiral selector, proteins and peptides by adding a polymer to the separation buffer, etc.)... 

Ishii, D., Hirose, A., and Horiuchi, I., Studies on micro-high-performance liquid-chromatography. 6.Application of microscale liquid-chromatographic technique to anion-exchange separation of halide ions. Journal of Radioanalytical Chemistry A5( ), 7-14, 1978. 

Two ion chromatographic techniques were utilized to quantify formic acid in both diesel engine exhaust and mine air subjected to diesel emissions. A commonly used anion separation system utilizing a weak borate eluent adequately separated the acids of interest in diesel exhaust. It was, however, affected by the presence of strong acids during subsequent consecutive analyses. 

The book commences with a chapter in which the principles and theory of various chromatographic techniques are discussed. Ion chromatography (Chapter 2) is a relatively recently introduced technique that has found extensive applications in the analysis of mixtures of anions and to a lesser extent of organic compounds and cations. Codetermination of anions and cations is possible. A variant of ion chromatography, namely electrostatic ion chromatography has to date found a very limited application to the determination of anions and is discussed in Chapter 3. 

Various miscellaneous column chromatographic techniques including ion pair, micelle, ion exclusion, size exclusion and gel permeation are discussed in Chapters 7-11. All of these techniques have found limited selected applications in the determination of organic compounds, cations and anions. 

The exchange of NaBr and KBr with HC1 reaches an equilibrium in which, near to room temperature, a mixed Cl /Br surface is at equilibrium with a gaseous HCl/HBr mixture whose composition depends on the surface anion ratio, but which is typically about 1 mole % HBr. This equilibrium was discovered in the laboratory of one of us (LGH) about eighteen years ago [96], but the topic proved difficult to pursue because of the difficulty of quantitative analysis of the gas mixture. Eventually, a temperamental but workable gas chromatographic technique [97] having provided the key to this analysis, we were able to show that the equilibrium is highly non-ideal [98]. The bromide surface apparently undergoes a two-dimensional phase transition, induced by HC1 or HBr adsorption, close to room temperature, in which the halide ions become mobile,... 

After their isolation by chromatographic techniques (anion-exchange chromatography, size exclusion, etc.), different analytical methodologies have been used to identify and quantify the polysaccharides in wine the most commonly used being the traditional methylation analysis followed by GC-MS (Doco and Bril-louet 1993). Polysaccharides have also been determined after solvolysis with anhydrous methanol containing HCl by GC-MS of their per-G-trimethylsilylated methyl glycosides (Vidal et al. 2003). Other techniques such as Fourier transform infrared spectroscopy (FTIR) have been more recently proposed (Coimbra et al. 2002,2005 Boulet et al. 2007). 

Even after production of printed circuit boards and semiconductor components, ion chromatography may be taken advantage of. Malfunctions are often caused by corrosive anions on the surface of printed circuits or inside, where the microchips are imbedded. Identification and quantification of these compounds with the aid of ion chromatographic techniques often represents a significant contribution for localizing the sources... 

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