| Start-up procedures | Start-up for all anion methods Start-up for all cation methods |
| Shut-down procedures | Shut-down for all anion methods Shut-down for all cation methods |
| Sample preparation | Sample prep for anions in water Sample prep for cations in water Sample prep for phosphatic shells (pdf) |
| Mostly obsolete | Eluant preparation |
We have two separate ion chromatograph systems, an older Dionex ICS-2100 for anions, and a newer Thermo Scientific (~Dionex) Integrion RFIC for cations. Both have conductivity detectors, identical autosamplers, and eluant generators. These instruments are capable of analyzing many inorganic ions and some organic acids at concentrations that extend down into the low ppb range. Samples must be in water solutions, not too concentrated, too acidic, or too alkaline. Here are the routinely analyzed ions and approximate detection limits.
| Anion system | Cation system | ||
|---|---|---|---|
| Species | Det. limit, ppb | Species | Det. limit, ppb |
| F | 1 | Li | 1 |
| Cl | 10 | Na | 10 |
| Br | 10 | K | 10 |
| NO2 | 10 | NH4 | 10 |
| NO3 | 10 | Mg | 20 |
| SO4 | 15 | Ca | 20 |
| PO4 | 25 | Sr | 50 |
| ClO** | 10 | Ba** | 100 |
| ClO2** | 15 | ||
| Glycolate** | 20 | ||
| Acetate** | 15 | ||
| Formate** | 10 | ||
| Propionate** | 25 | ||
| Methyl sulfonate** | 25 | ||
| Oxalate* | 50 | ||
| *Low detection limits only possible in low sulfate samples. | |||
| **Requires additional standards. Check for interferences (except Ba). | |||
