Capillary electrophoresis determinations of trace concentrations of inorganic ions in large excess of chloride: Soft modelling using artificial neural networks for optimisation of electrolyte composition
✍ Scribed by Martin Muzikárcaron;; Josef Havel; Miroslav Macka
- Publisher
- John Wiley and Sons
- Year
- 2003
- Tongue
- English
- Weight
- 151 KB
- Volume
- 24
- Category
- Article
- ISSN
- 0173-0835
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✦ Synopsis
Abstract
In this work, using a combination of experimental design (ED) and artificial neural networks (ANN), the composition of a triethanolamine‐buffered chromate electrolyte was optimised for determination of sulphate anions in the presence of high chloride excess. The optimal electrolyte, allowing a baseline‐resolved separation of sulphate from chloride present in a 1500 multiple excess in less than 170 s, consists of 10 mmol/L CrO~3~, 2 mmol/L hexamethonium hydroxide, 10% methanol, and triethanolamine added to adjust the pH to 8.0. The method is suitable to a wide concentration range of chloride (4–1757 mg/L) and sulphate (4–590 mg/L) with linear calibration plots (R^2^ = 0.9937–0.9999). Relative standard deviations are less than 2.0% for both anions for migration times and peak areas. The detection limits (hydrodynamic injection of 1 s) were 0.6 mg/L for sulphate and 0.5 mg/L for chloride. The method was successfully applied to determination of sulphate in mineral waters containing a high chloride concentration and to determination of sulphate traces in an anticancer drug injection preparation containing a physiological level of chloride. It was shown that α‐cyclodextrin as an electrolyte additive has a significant potential for further increasing the separation selectivity for inorganic anions.