Flow-injection spectrophotometric determination of gold using 5-(4-sulphophenylazo)-8-aminoquinoline

• Published in: Analytica chimica acta Vol. 401; no. 1; pp. 237 - 241
• Main Authors: Zuotao, Zeng, McCreedy, T, Townshend, Alan
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 29.11.1999; Elsevier
• Subjects: 5-(4-Sulphophenylazo)-8-aminoquinoline (SPA); Analytical chemistry; Chemistry; Exact sciences and technology; Flow injection (FI); Gold; Spectrometric and optical methods; Spectrophotometry; Gold; 5-(4-Sulphophenylazo)-8-aminoquinoline (SPA); Flow injection (FI); Spectrophotometry; Quaternary ammonium compound; Trace analysis; Chemical analysis; Gold Complexes; Cationic surfactant; Organic ligand; Visible spectrometry; Transition metal Complexes; Aqueous solution; Micellar solution; Flow injection
• ISSN: 0003-2670; 1873-4324
• DOI: 10.1016/S0003-2670(99)00498-5

Gold (0–75 μg ml −1) was determined spectrophotometrically at 605 nm in a flow injection (FI) system based on the reaction of gold(III) and 5-(4-sulphophenylazo)-8-aminoquinoline (SPA) in the presence of cetyltrimethylammonium bromide (CTAB). The carrier stream was 1% (w/v) disodium ethylenediaminetetraacetate and the reagent streams were 2.0 × 10 −4 M SPA and 0.6% (w/v) sodium hydroxide solution. The sample solution was mixed with 0.2% (w/v) CTAB solution prior to injection. The various chemical and physical variables were optimised and a study of interfering ions was carried out. The relative standard deviation for the determination of 5 μg ml −1 gold was 0.9% ( n = 10) and the limit of detection (blank signal plus three times the standard deviation of the blank) was 1.1 μg ml −1, both based on injection volumes of 60 μl. The method has been successfully applied to the determination of gold in ores and anode slimes.