Ion Chromatograph (IC)
The Dionex ICS-1100 is a dual channel (anions and cations) IC and includes:
- Dionex ICS-1100 Ion Chromatograph with Anion and Cation Self-Regenerating Suppressors (4mm)
- AS40 Automated Sampler
- AS14 Column (4 x 250mm)
- CS12A Column (4 x 250mm)
- AS-DV Automated Sampler
- Chromeleon 7.0 - WorkStation
Theory of Operation
Anions:
A sample is introduced into a stream of carbonate-bicarbonate eluent and passed via high pressure through a highly basic ion exchange column where anions are separated based on their relative affinity to the column.
Cations:
A sample is introduced into a stream of 22mN H2SO4 eluent and passed via high pressure through an ion exchange column where cations are separated based on their relative affinity to the column.
Analysis:
The peaks with eluent are passed through self-regenerating micromembrane suppressors (anions or cations) where baseline effects from the eluent are reduced. The conductivity of individual peaks is then measured with a conductivity cell.
Available Methods:
Current methods are for trace analysis in water.:
- WICA (Anions-Trace-Water)
- WICA1 (Anions-Higher level)
- WICC (Cations-Trace-Water)
WICA- Water-Anions by IC
| Anion (Cl) | Range (ppm) |
| Phosphate (o-PO4) | 0.050...1.00 |
| Chloride (Cl) | 0.050...1.00 |
| Nitrite (NO2-N) | 0.025...1.0 |
| Nitrite (NO2-N) | 0.025...1.0 |
| Nitrate (NO3-N) | 0.025...3.2 |
| Sulphate (SO4) | 0.250...25.0 |
Criteria for acceptance of samples are:
- Samples do not have visible suspended solids and are not cloudy
- Maximum analytical range < 100 ppm for any analyte.
- No organic materials, i.e. humic acid. Colored samples may require cleanup before analysis.
- Sample pH between 0 and 14
Acceptable sample bottles are glass or polyethylene. Store at 4 degC. Holding times recommended by the EPA for trace anions is immediate to 48 hours (sulphate=3 days). Samples must not be frozen.
WICC : Water-Cations by IC
| Anion (Cl) | Range (ppm) |
| Sodium (Na) | 0.100 - 10.0 |
| Ammonium (NH4-N) | 0.010 - 2.50 |
| Potassium (K) | 0.100 - 10.0 |
| Magnesium (Mg) | 0.100 - 10.0 |
| Calcium (Ca) | 0.100 - 10.0 |
Criteria for acceptance of samples are:
- Samples do not have visible suspended solids and are not cloudy
- Maximum analytical range < 100 ppm for any analyte.
- No organic materials, i.e. humic acid. Colored samples may require cleanup before analysis.
- Sample pH between 0 and 14
Acceptable sample bottles are polyethylene. Store at cool to 4 C. Glass can cause Na leaching.Filtration of samples through 0.45 um filters and storage at 4 C will stabilize all analytes for 6 weeks, except NH4+ which is stable for 4 days.