Column ion chromatography

In the past, KOH eluent was usually contaminated with CO -. When CO passes through the suppressor after the ion chromatography column, it is converted into H2C03, which has some electrical conductivity that interferes with detection of analytes. In gradient... 

Waste water Addition of HN03 to sample and evaporation redissolution in water (pH should be 2) separation on ion chromatography column using TPPS4/PAR/NaCI/Na2B407-Na0H as post-column derivatization agent Spectro- photometry 50 g/L No data Yan et al. 1989... 

B. J. Johnson, Sulfite-disulfite equilibrium on an ion chromatography column, J. Chromatogr.. 508,271,1990. 

The concentration of carbon dioxide reduction products (formic acid, formaldehyde, and methanol) in the reactor at the end of each run is listed in Table 1. The methanol concentration was determined by gas chromatography using a Porpac T column. Formic acid was determined with an Dionex ion chromatography column, and the formaldehyde was determined with a colorimetric chromatropic acid analysis (J ). We did not examine the solution or gas phase for methane. 

Ion chromatography columns packed with appropriate cationic or anionic polymer resin. 

Figure 12.5 Separation of a seven-anion standard with single-column ion chromatography. Column [Chromatographic conditions IC-Pak Anion HR, 4.6 mmx7S mm. Waters Corp. Eluent borate/gluconate. Sample seven-anion standard (1) fluoride (2) bicarbonate (3) chloride (4) nitrite (S) bromide (6) nitrate (7) phosplmt (8) suUite. Detection conductivity. (Qiromatogram courtesy of Waters Corp.)...

At the beginning, with ion chromatography, column materials utilized particles greater than 40 p.m and generated only about 120 and 300 theoretical plates efficiency. In the first commercial column used for IC (Dionex AS-1), the particle size was reduced to 25 p.m and efficiencies increased to —700 theoretical plates. Modem high-capacity columns have efficiencies over 5000 plates (for 4 X 250 mm column dimensions) and 5 p-m particle size. ... 

An alternative to the acid digestion of solid samples is fusion under alkaline conditions. The procedure is usually very labor intensive, takes a long time, and involves a high risk of eiTOTS from contamination and loss of analyte. This method can be used for the determination of fluoride and chloride in geological materials after fusion with sodium carbonate and subsequent injection into an ion chromatography column. 

Consider a spherical protein in water with charge -q (q > 0) at a distance Ro from a planar ion chromatography column surface with net positive charge, shown in Figure 23.7. 

Ci4 alkyltrimethylammonium chloride, Ci4-Cifi alkyldimethylbenzyl-ammonium chlorides, benzethonium chloride assay MPIC-NSl mobile phase ion chromatography column, 4 x 200 mm 70 30 or 75 25 CH3CN/O.OO5 M HCIO4 Conductivity 13 ... 

To minimize the mobile phase s contribution to conductivity, an ion-suppressor column is placed between the analytical column and the detector. This column selectively removes mobile-phase electrolyte ions without removing solute ions, for example, in cation ion-exchange chromatography using a dilute solution of HCl as... 

Ion-exchange chromatography in which conditions are adjusted so that an ion-suppressor column is not needed. 

In this experiment phosphate is determined by singlecolumn, or nonsuppressed, ion chromatography using an anionic column and a conductivity detector. The mobile phase is a mixture of n-butanol, acetonitrile, and water (containing sodium gluconate, boric acid, and sodium tetraborate). 

Schematic diagram of an orthogonal Q/TOF instrument. In this example, an ion beam is produced by electrospray ionization. The solution can be an effluent from a liquid chromatography column or simply a solution of an analyte. The sampling cone and the skimmer help to separate analyte ions from solvent, The RF hexapoles cannot separate ions according to m/z values and are instead used to help confine the ions into a narrow beam. The quadrupole can be made to operate in two modes. In one (wide band-pass mode), all of the ion beam passes through. In the other (narrow band-pass mode), only ions selected according to m/z value are allowed through. In narrow band-pass mode, the gas pressure in the middle hexapole is increased so that ions selected in the quadrupole are caused to fragment following collisions with gas molecules. In both modes, the TOF analyzer is used to produce the final mass spectrum.

The total stationary-phase volume required to process a given feed stream is proportional to the inlet concentration and volume of the feed. For example, for a typical inlet concentration of protein of 10 g/L, in a 100 L volume of feed, a column volume of at least 100 L is needed for size-exclusion chromatography. In comparison, an ion-exchange column having an adsorption capacity of 50 g/L would only require 20 L of column volume for the same feed. 

Leucrose, 6-0-(a-D-glucopyranosyl)-P-D-fmctopyranose [7158-70-5] is synthesized from sucrose usiag a dextranase enzyme from l euconostoc mesenteriodes and a small proportion of fmctose (2%). Pfeifer Langen of Germany have developed a production process for leucrose that iavolves extraction of the enzyme, treatment with 65% aqueous solution of sucrose and fmctose (1 2 wt/wt) at 25°C, separation of the product from fmctose by ion-exchange column chromatography, and crystallization. The product has not yet been launched on the market as of this writing (1996). 

Dionex Corporation - Manufacturers of liquid chromatography systems (IC and HPLC), chromatography software data systems, reversed-phase and ion-exchange columns, and accelerated solvent extraction systems... http //www.dionex.com. 

S. R. Villasenoi, Matrix elimination in ion chromatography by heart-cut column switcliing techniques , 7. Chromatogr. 602 155-161 (1992). 

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