Comparison of four chromogenic reagents for the flow-injection determination of aluminum in water

✍ Scribed by Oddvar Røyset

• Book ID: 104100540
• Publisher: Elsevier Science
• Year: 1985
• Tongue: English
• Weight: 507 KB
• Volume: 178
• Category: Article
• ISSN: 0003-2670
• DOI: 10.1016/s0003-2670(00)86272-8

✦ Synopsis

Pyrocatechol violet (PCV), aluminon, eriochrome cyanine R (ECR) and eriochrome cyanine R with cetyltrimethylammonium bromide (ECR/CTA) are compared as chromogenic reagents for the flow-injection determination of aluminium in water. The detection limit of the ECR/CTA method is 1 rg Al 1-l. The detection limits of the PCV and ECR methods are 5 rg Al 1-l. The aluminon method is the least sensitive, with a detection limit of 50 rg Al 1-l. Interference from iron, fluoride, phosphate and the acidity of the sample were investigated. The interference from iron is suppressed by hydroxylammonium chloride/l,lO-phenanthroline in the PCV and ECR/CTA methods at concentrations less than 5 mg Fe 1-l. In the ECR and aluminon methods, iron (< 5 mg 1-l) is masked by ascorbic acid. Fluoride at <0.2 mg 1-l can be tolerated in all methods.

The aluminon method can tolerate up to about 500 mg 1-l phosphate-P, but phosphate interferes at concentrations higher than 5 mg P 1-l in the three other methods. All methods are sensitive to changes in acidity of the samples; the acidity should be 0.08-0.12 M HCl.