Ion chromatography/ICP

Figure 1 Flowchart showing the basic procedures using the oxygen flask method for elemental analysis. IC, ion chromatography ICP-AES, inductively coupled plasma-atomic emission spectrometry ISE, ion selective electrodes.

CNDA, 3-carboxy-2-naophthylamine-A/,A/-diacetic acid DBS, dodecylbenzenesuifonic acid iC, ion chromatography iCP-AES, inductiveiy coupied piasma-atomic emission spectrometry iSE, ion seiective eiectrodes TEA, tetrabutyiammonium hydroxide. 

Separation and detection methods Ion chromatography is routinely used for the isolation of bromate. Diverse detection methods are mentioned in the literature, including isotope dilution analysis (Creed and Brockhoff 1999), conductivity measurement (Jackson et al. 1998), fluorimetric determination (Gahr et al. 1998), ICP-MS (Seubert and Nowak 1998) and spectrophotometry (Achilii and Romele 1999),... 

Bayon, M. M., Rodriguez Garcia, A., Garcia Alonso, J. I., and Sanz-Medel, A., Indirect determination of trace amounts of fluoride in natural waters by ion chromatography a comparison of on-line post-column fluorimetry and ICP-MS detectors, Analyst, 124, 27, 1999. 

HPLC (in both NP and RP modes) is quite suitable for speciation by coupling to FAAS, ETAAS, ICP-MS and MIP-MS [571,572]. Coupling of plasma source mass spectrometry with chromatographic techniques offers selective detection with excellent sensitivity. For HPLC-ICP-MS detection limits are in the sub-ng to pg range [36]. Metal ion determination and speciation by LC have been reviewed [573,574] with particular regard to ion chromatography [575]. 

Bettinelli and Spezia [750] applied ion chromatography with an ICP-MS to the determination in seawater of 20 metallic elements in amounts down to 1-50 ppt. 

To make this conclusion more reliable, we applied the above statistical comparison procedure to independent data on the chemical composition of melted snow samples, which were collected in the vicinity of a nickelprocessing plant, on the Kola Peninsula [2], and an industrial megalopolis [4], According to these data, chemical analysis of melted snow was conducted by ICP-MS, ICP-AES and ion chromatography using certified reference materials SLRS-2 of the National Research Council (Canada) and NIST, 1643c (US) [2], Statistical analysis of these data revealed that... 

Major and trace element concentrations in the acidified samples were determined via ICP-MS (inductively coupled plasma mass spectrometry) and ICP-OES (inductively coupled plasma optical emission spectroscopy) at the GSC s Geochemistry Research Laboratory. Dissolved anion concentrations were measured by 1C (ion chromatography) on the unacidified samples, also at the GSC s Geochemistry Research Laboratory. Characterization of the sediment mineralogy and texture by XRD (X-ray diffraction), SEM (scanning electron microscopy) and TEM (transmission electron microscopy) is ongoing. 

The compound is cautiously dissolved in nitric acid and the solution is appropriately diluted for the analysis of antimony by AA spectrophotometry or ICP emission spectrophotometry and fluoride ion is determined by ion—selective electrode or ion chromatography. 

Elemental composition Cd 41.29%, Br 58.71%. The salt is dissolved in water and the aqueous solution is analyzed hy AA or ICP spectrophotometry. The bromide anion in the aqueous solution may he measured hy ion chromatography. Appropriate dilution may be needed for analysis... 

Elemental composition Cd 30.69%, I 69.31%. A small amount of salt is weighed accurately, dissolved in water, appropriately diluted, and analyzed by AA or ICP spectrophotometry. Iodide anion at similar trace concentrations may be analyzed by ion chromatography. 1 anion may be identified by adding a few drops of 6MHNO3 to a few drops of the aqueous solution of the salt, followed by the addition of ImL 0.1 MFeCls solution and ImL methylene chloride. A purple or pink bottom layer after shaking indicates the presence of iodide. 

Elemental composition Ca 36.11%, Cl 63.89%. An aqueous solution of the compound may be acidified and analyzed for calcium by AA or ICP methods (see Calcium). The solution may be analyzed for chloride ion by ion selective electrode, ion chromatography or by argentometric titration. 

Elemental compostion Ce 25.56%, H 1.47%, N 20.44%, 0 52.53%. The aqueous solution of the compound may be analyzed for Ce by AA or ICP spectrophotometry. Also, the solution may be measured for NH4 ion by ammonium ion-selective electrode and the NO3 ion by nitrate ion-specific electrode, ion chromatography or cadmium-reduction colorimetry. For all these measurements, the solution may require sufficient dilutions. For quantitation, its solution may be standardized by titration with a reducing agent such as sodium oxalate in the presence of iron and ferroin indicator. 

Elemental composition Ce 42.96%, N 12.88%, O 44.15%. The aqueous solution of this water-soluble compound may be analyzed directly for Ce (without any acid digestion) by AA or ICP spectrophotometry, and for the nitrate ion by ion chromatography or nitrate ion-selective electrode. The solution may require sufficient dilution for analysis. 

Elemental composition Ce 42.18%, S 19.30%, O 38.53%. It is digested with nitric acid, diluted appropriately and analyzed for Ce by AA or ICP spectroscopy (see Cerium). The compound may be dissolved in small quantities of water (forms a basic salt when treated with large a volume of water). The solution is analyzed for sulfate ion by gravimetry following precipitation with barium chloride. Alternatively, the compound is dissolved in hot nitric acid and the solution analyzed for sulfate by ion-chromatography. 

Elemental composition Cr 42.31%, Cl 57.69%. The metal may be analyzed by AA, ICP, or other instrumental techniques. Chloride may be measured by ion chromatography or by using a chloride ion selective electrode. Because of the blue color of its aqueous solution, end point detection in titrimetric methods may be difficult. 

Elemental composition Cr 32.84%, Cl 67.16%. Chromium(HI) chloride may be solubilized in water by a reducing agent and the aqueous solution may be analyzed for chromium by AA, ICP, or other instrumental techniques. Alternatively, the compound may be digested with nitric acid, brought into aqueous phase, diluted appropriately, and analyzed for the metal as above. The aqueous solution (when a nonchloride reducing agent is used for dissolution of the anhydrous compound in water) may be analyzed for chloride ion by ion chromatography or chloride-selective electrode. The water-soluble hexahydrate may be measured in its aqueous solution as described above. 

The aqueous solution may be analyzed for chromium by AA or ICP techniques. Chromium(III) may be measured by ion chromatography. Additionally, the compound may be decomposed thermally to chromium(lll) oxide, Cr203, which can be identified by x-ray techniques. Water content of the hydroxide may be measured by gravimetry. 

Elemental composition Cr 52.00%, 0 48.00%. The compound may he identified from its dark red color. Other color phases are noted above. Chromium may he measured in the aqueous phase hy AA, ICP or x-ray techniques, or in the solid phase hy x-ray methods. Hexavalent chromium (Cr6+) may he analyzed hy ion chromatography. For this, the aqueous sample is adjusted to pH 9 to 9.5 with a concentrated buffer (ammonium sulfate and ammonium hydroxide mixture) and mixed into the eluent stream of the buffer. Cr " is separated from Cr + on a column, and derivatized with an azide dye as a colored product measured at 530 nm, which is identified from its retention time. (APHA, AWWA, and WEF. 1999. Standard Methods for The Examination of Water and Wastewater, 20th ed., Washington, DC American Public Health Association.)... 

Elemental composition Co 45.39%, Cl 54.61%. Aqueous solution of the salt or acid extract may be analyzed for cobalt by AA, ICP, or other instrumental techniques following appropriate dilution. Chloride anion in the aqueous solution may be measured by titration with silver nitrate using potassium chromate indicator, or by ion chromatography, or chloride ion-selective electrode. 

Elemental composition Co 60.80%, F 39.20%. Cobalt(II) fluoride is dissolved in hot nitric acid, the solution is appropriately diluted with water and analyzed for cobalt by AA or ICP spectrophotometry (see Cohalt). A small amount of salt dissolved in cold water (hot water may partially decompose forming oxyfluoride, C0F2 CoO H2O) may he analyzed for fluoride ion by fluoride ion-selective electrode or ion chromatography. 

Elemental composition Co 18.84%, 1 81.16%. C0I2 may be identified from its varying colors in different solvents. Under varying conditions, its aqueous solution may be analyzed for cobalt by AA, ICP or other instrumental techniques after appropriate dilution (see Cobalt). Iodide anion may be analyzed in sufficiently diluted aqueous phase hy ion chromatography. Also, the analy-... 

Elemental composition (anhydrous salt) Co 32.33%, N 15.31%, 0 52.47%. The aqueous solution may be analyzed for cobalt by AA or ICP or other instrumental methods. The nitrate anion may be measured by ion chromatography or nitrate ion-selective electrode. The solutions may require sufficient dilution for all these measurements. 

Elemental composition Co 38.03%, 8 20.68%, O 41.29%. 8ohd cobalt(Il) suhate is brought to aqueous phase by acid digestion, appropriately diluted, and analyzed for cobalt by flame or furnace AA or ICP. It also may be determined in the solid crystalline form by x-ray methods. The suhate anion may be measured by dissolving an accurately measured small amount of salt in measured quantities of water and analyzing the solution by ion chromatography. 

Elemental composition Cu 64.18%, Cl 35.82%. Copper(I) chloride is dissolved in nitric acid, diluted appropriately and analyzed for copper by AA or ICP techniques or determined nondestructively by X-ray techniques (see Copper). For chloride analysis, a small amount of powdered material is dissolved in water and the aqueous solution titrated against a standard solution of silver nitrate using potassium chromate indicator. Alternatively, chloride ion in aqueous solution may be analyzed by ion chromatography or chloride ion-selective electrode. Although the compound is only sparingly soluble in water, detection limits in these analyses are in low ppm levels, and, therefore, dissolving 100 mg in a liter of water should be adequate to carry out aU analyses. 

---