ABOUT THE INSTRUMENTATION

Ion Chromatography (IC) is a very sensitive chromatographic method for the routine identification and quantification of many cations (e.g., sodium, Na⁺) and anions (e.g., chloride, Cl^-) in aqueous solutions.

This well-known liquid chromatographic technique separates analytes according to their affinity for the separation column packed with an ion-exchange resin of low capacity.

During the analysis, the effluent from the separation column is passed through a suppressor column to neutralize the counter-ions of the eluent and thus lower its conductivity. With the resulting low background conductivity, the ions in solution are detected with high sensitivity (ppb range) using conductivity detection.

The separated ions are identified qualitatively based on the retention time required by each ion to pass through the column and quantitatively through integration of signal intensity which is proportional to the analyte concentration.

Instrumentation:

• Dionex ICS-2000 RF Ion Chromatograph
  
  
• AS40 Automated Sampler
  
  
• Dionex Chromeleon CMS Software

ADDITIONAL INFORMATION

The ICS-2000 RF Ion Chromatograph is a basic isocratic IC instrument using selected ion exchange columns to effect separation of the ions, digital conductivity to detect the eluting ions and Dionics’ auto-suppression technology to improve detection sensitivity. A AS40 allows unattended operation and overnight runs.

This instrument has been used for the following analyses:

• Cation and anion survey scans in water and mixed organic/aqueous solutions
  
  
• Identification and quantification of ionic contaminants remaining on printed circuit boards, flexible circuit, aerospace and medical parts. The ions can be simply washed off with DI water or extracted by heating the parts in disposable Kapak bags containing water or heated with water above 100 ^oC in Teflon lined Parr bombs depending upon the client’s requirements. Organic co-solvents can also be added to the DI water to improve wettability and extraction efficiency depending upon the substrate.
  
  
• Detection and quantification of organic acids; e.g., formic acid, acetic acid, malonic acid, etc.