Inorganic ions, quantitative determination

Ion chromatography permits the determination of both inorganic and organic ionic species, often in concentrations of 50 g L"1 (ppb) or less. Since analysis time is short (frequently less than 20 minutes) and sample volumes may be less than 1 mL, IC is a fast and economical technique. It has found increasing application in a number of different areas of chemical analysis and particularly for the quantitative determination of anions. The state-of-the-art has been reviewed.26... 

By employing both instrumental and conventional analytical techniques on solvent extracts of an elastomeric closure formulation, extractables can be isolated, the inorganic ions determined quantitatively, and the organic components functionally characterized... 

Quantitative determination of inorganic ions in vitamin formulation calcium, zinc, iron... 

Alkaline earth and transition metal ions can be converted to negatively charged complexes by reaction with different ligands and can be separated in the same mixture with inorganic anions using anion exchange methods. This makes possible the use of standard IC equipment for their quantitative determination and this approach has proved popular (see recent applications in Table 2). 

Odanaka and coworkers have reported that the combination of gas chromatography with a multiple ion detection system is useful for the quantitative determination of inorganic, mono-, di- and trimethylarsenic oxide compounds, and this approach is applicable to the analysis of environmental and biological samples. The limit of detection for a 50-ml sample was 0.2-0.4ngmU of arsenic. Recoveries of all four arsenic species from river water ranged from 85% to 100% (Table 17). 

B.W. Hoffman and G. Schwedt, Application of HPLC to inorganic analysis. Part VII. Comparison between pre-column- and on-column derivatizalion for separation of different metal oxinaies quantitative determination of manganese(II) besides manganese(lll) ions, J. HRC and CC, 5.439, 1982. 

UV /VIS radiation absorption spectroscopy, spectrophotometry determinations of aromatic and unsaturated organic compounds, including natural products direct and indirect quantitative determination of inorganic ions, organic molecules, and biochemicals... 

After the first qualitative studies of lithium-, sodium-, calcium-, and silver-halides and other inorganic salts with complex anions had revealed the types of ion occurring in FD mass spectra and the high sensitivity of the method for metal cations had been demonstrated the principal question arose whether quantitative data could be obtained. If so, it was essential in the use of FDMS as an analytical technique for metals to evaluate the sensitivity, precision and accuracy for these determinations. Since pilot tests showed an extraordinary sensitivity for cesium the first approach to the quantitive determination of metals by FD was started with this alkali metal. 

An aqueous sample obtained from the environment that may be expected to contain dissolved inorganic salts can be injected into a properly installed and optimized ion chromatograph. The concentration of the most common inorganic anions and corresponding cations can be quantitatively determined. The instrumentation available in our laboratory is that manufactured by the Dionex Corporation in the early to mid-1980s. 

There are countless situations where an ion-chromatographic determination wiU provide a fast and satisfactory answer to an analytical problem. Some of these examples may require the development of appropriate sample pretreatment or sampling techniques. For example, how does one sample fog IC determination of trace inorganic ions in very pure water often requires some form of sample preconcentration to achieve the requisite limits for quantitative detection. 

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