Firma:              Dionex

Modell:                         4000i

Kommentar:     Dokumente engl.

General Operating Instructions

The Fast Sep Cation II is used with the Fast Sep Cation I in the Column Switching Mode to obtain the fastest possible results for the simultaneous analysis of both alkali and alkaline earth metals under isocratic eluant conditions. Figure 3-1 is a representation of the separation scheme.

Fig. 3-1 Representation of an Analysis Using Column Switching between the Fast Sep Cation I and II columns

When the sample is injected, the column switching valve should be in the OFF position: the eluant flows first through the Fast Sep Cation II column and then through the Cation I column. The divalent cations in the sample will be retained by the Cation Il column, while the monovalent ca­tions are essentially unretained by this column and move to the Cation I column where they are separated.

At 40 seconds (0.6 min.) after injection the valve is switched ON. The eluant now flows first through the cation I column and then through the Cation II column. This prevents the divalent ca­tions in the sample from going through the Cation I column, providing rapid divalent cations separation by the Cation II column.

If you have a Gradient Pump Module (GPM), you can control the injection valve and the column switching valve automatically through GPM valves 5 and 6, respectively. The program would be as follows:

* this time depends on the type of the analysis

GENERAL OPERATING CONDITIONS

Eluant components:           HCI and 2,3-diaminopropionic acid monohydrochloride (DAP.HCI) Eluant flow rate: 2.0 mL/minute

Regenerant:                        0.1 M tetrabutylammoniumhydroxide (TBAOH)

Regenerant flow rate:         greater or equal to 5 mL/minute

Detector Range:                 10 µS full scale or as required

Sample loop:                      50 µL (or as required)

CHEMICALS REQUIRED

It is very important for the eluant to be as free of metalic impurities as possible. Thus, chemicals and water used should be of the greatest available purity.

• Only use concentrated HCI, Ultrex grade or Baker Instra-Analyzed for Trace Metals.

• Use DL-2,3-Diaminopropionic acid monohydrochloride (DAP.HCI) from Fluka Chemical Corporation ONLY

• Use Dionex Tetrabutylammonium hydroxide (TBAOH), 0.1 M (P/N 39602)

• Use deionized water, 18 MOhm or better.

SYSTEM REQUIREMENTS

The Anion MicroMembrane Suppressor (AMMS-1) is designed to be run on a Series 2000i or 4000i Ion Chromatograph (IC) equipped with an anion exchange column set and a Conductivity Detector Module (CDM). The Anion MicroMembrane Suppressor (AMMS-1) is installed immediately after the analytical column and before the conductivity detector in the column compartment of the chromatography module.

INTRODUCTION TO ANION ANALYSIS ELUENT SUPPRESSION

The Anion MicroMembrane Suppressors, AMMS-II and AMMS (2mm) provide high capacity suppression while adding a minimum of dead volume to the analytical system. The AMMS (2mm) is specially designed to be used with 2mm ion chromatography columns and is only compatible with 2mm chromatography systems. Its equivalent suppression capacity is greater than the suppression capacity achieved in the Anion MicroMembrane Suppressor used with 4mm ion chromatography column systems (AMMS-11). The ability of the AMMS-II and AMMS (2mm), to provide continuous suppression of traditional eluents, as well as eluents as concentrated as 0.1 M NaOH, significantly expands the capabilities of anion exchange ion chromatography.