Columns Dionex

Two anion exchange columns Dionex CarboPac PA1 plus a guard column and CarboPac MAI column with a guard column were used for separation procedure (High Performance Anion Exchange Chromatography). 

Figure 26-7 Anion separation by ion chromatography with a gradient of electrolytically generated KOH and conductivity detection after suppression. Column Dionex lonPac AS11 diameter = 4 mm flow = 2.0 mL/min. Eluent 0.5 mM KOH for 2.5 min, 0.5 to 5.0 mM KOH from 2.5 to 6 min 5.0 to 38.2 mM KOH from 6 to 18 min. Peaks (1) quinate, (2) F, (3) acetate, (4) propanoate, (5) formate,...

Fig. 1. Simultaneous separation and detection of anions and cations on a latex agglomerate column. Column Dionex HPIC-CS5 cation exchange column (250X2 mm) with precolumn HPIC-CG5 (50 X 4 mm) eluent 0.5 mM copper sulfate, pH 5. 62 flow rate 0.5 ml/min sample volume 20 gl containing 0.1 m M of each ion detection two potentiomet-ric detectors equipped with different ion-selective electrodes in series. Peaks (1) chloroacetate, (2) chloride, (3) nitrite, (4) benzoate, (5) cyanate, (6) bromide, (7) nitrate, (8) sodium, (9) ammonium, (10) potassium, (11) rubidium, (12) cesium, (13) thallium. Reprinted with permission from [10].

Figure 10.1 Ion-exchange chromatographic separation of main anions found in water using a Dionex HPLC and AS-11 HC column. Conditions column Dionex AS-11 HC 250 X 4 mm solvent Milli-Q water and 3 mM NaOH for 6 mins then to 30 mM NaOH over 15 min flow rate 1.5 ml/min suppressed conductivity detection.

Figure 10.3 HPLC trace of a suspect apple juice run on Dionex HPLC using PA-10 column and PAD detection. Conditions column Dionex PA-10 250 X 4 mm solvent = 100 mM sodium hydroxide in HPLC water PAD detection sample diluted 1 100 in water prior to filtration and analysis.

Figure 10.8 HPLC separation of organic acids and anions by ion-exchange chromatography and conductivity detection. Conditions column Dionex AS-11 250 X 4 mm suppressed conductivity...

Figure 7. Ion chromatographic separation of ammonium ion (3) from sodium (1) and calcium (2) ions with a concentration ratio of sodium to ammonium of 60,000 1. Column Dionex CS15 eluent sulfuric acid and 18-crown-6. (from ref. 32)...

When using conventional ion chromatographic separation techniques, it is possible that other matrix anions also common to non saline waters may coelute with bromide. For example, bromide and nitrate elute simultaneously using a standard anion separator column (Dionex No. 30065), standard anion suppressor (Dionex No. 30366) and standard eluant (0.003M sodium bicarbonate/0.0024M sodium carbonate). 

Weak anion-exchange column (Dionex AS4A) with elution in a gradient of HNO3 allowed the separation of 8 species within 12 min on-line ICP-MS. 

Different pretreatment procedures tested, centrifugation finally adopted, separation carried out ion-exchange column (Dionex AS 14) with carbonate buffer as the mobile phase... 

The properties and performance of a commercial weak-acid resin column (Dionex CS12) have been described [41]. The substrate is a highly cross-linked, macroporous ethylvinylbenzene-divinylbenzene polymer with a bead diameter of 8 pm, a pore size of 6 nm, and a specific surface area of 3(X) m /g. In a second step, this substrate was grafted with another polymer containing carboxylate groups. The exchange capacity is listed as 2.8 mequiv/column for a 250 mm x 4 mm i.d. column. With this column, simple eluents such as hydrochloric or methanesulfonic acid can be used to separate mono- and divalent cations rapidly and efficiently under isocratic conditions. 

Thermo Fisher Scientific offers two ion-exclusion columns Dionex lonPac ICE-ASl and AS6. The former is a moderately hydrophilic, microporous poly (styrene-co-divinylbenzene)-based cation exchanger with a particle diameter of 7.5 pm and ion-exchange capacity of 27 mequiv/column, functionalized with sulfonate groups. The lonPac ICE-ASl is primariliy used for the separation of weak inorganic acids, short-chain fatty acids, and alcohols. Difficulties are encountered, however, in the separation of aliphatic mono-, di-, and tricarboxylic acids. These acids elute from such stationary phases within the totally permeated volume. The selectivity of the separation in this retention range is usually very poor. Since the totally permeated volume is determined... 

FIGURE 10.8 Chromatogram of carbohydrates in orange juice. Peak identities a, xylitol b, sorbitol c, glucose d, fructose e, sucrose. Chromatographic conditions CarboPac PAl anion-exchange column (Dionex), 100 mM NaOH mobile phase with a 1 mL/min flow rate PAD at an Au electrode. (Reprinted from Zook, C.M. and LaCourse, W.R., Curr. Sep., 14(2), 48-52, 1995. With permission.)... 

FIGURE 10.10 Chromatograms of saccharides in (A) fruit yogurt, (B) candy, and (C) infant formula. Peak identification 1, D-galactose 2, D-glucose 3, saccharose 4, D-fructose 5, lactose 6, maltose 7, maltotriose 8, maltotetraose 9, maltopentaose 10, maltohexaose 11, maltoheptaose. Conditions Linear gradient from 0 to 0.25 M sodium acetate in 0.1 M sodium hydroxide on CarhoPAC PAl column (Dionex). Detection Pulsed amperometric detection (PAD). (Reprinted from Van Riel, J. and Olieman, C., Carbohydr. Res., 215, 39-46,1991.)... 

FIGURE 10.15 Separation of 17-component amino acid hydrolyzate. Conditions Column, Dionex AS-8 gradient. Peaks (25 nmol each, except 12.5 nmol for cystine) a, arginine b, lysine c, threonine d, alanine e, glycine f, serine g, valine h, proline i, isoleucine j, leucine k, methionine 1, histidine m, phenylalanine n, glutamic acid o, aspartic acid p, cystine and q, tyrosine. (Reprinted from Welch, L.E., LaCourse, W.R., Mead, D.A., Jr., and Johnson, D.C., Ana/. Chem., 61, 555, 1989.)... 

Fig. 2.2. Ion chromatograms of a synthetic river water (277 mg chloride, 69 mg sulfate, 5 mg 1 phosphate) spiked with 400 micrograms selenium as selenite and 400 micrograms selenium as selenate recorded with a conductivity detector and a Hitachi Zeeman graphite furnace atomic absorption spectrometer (GFAAS) as the selenium-specific detector (Dionex Model 16 ion chromatograph, 1.0 ml sample, 50 x 3 mm anion precolumn Dionex 30008 mobile phase 0.008 M aqueous Na2C03, 0.46 ml min 150 X 3 mm anion separator column Dionex 30589 250 x 3 mm anion suppressor column Dionex 30066. GFAAS drying 120°, 60 sec no ashing atomization 2500°, 6 sec Se lamp 10 niA, 196.0 nm 80 sec between injections retention time in min). Redrawn from the Journal of Chromatography [9] by permission of Elsevier Science Publishers and the authors.

Suppressor column Dionex AMS, preproduction protot/pe. Membrane suppressor... 

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