کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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1244029 | 969679 | 2007 | 5 صفحه PDF | دانلود رایگان |
A highly selective and simple flow injection method is reported for the determination of Au(III) in jewel samples. The method is based on the catalytic effect of Au(III) on the oxidation of 4-amino-4′-methoxydiphenylamine hydrochloride (Variamine Blue B base, VB) by KIO3. The colored reaction product was monitored spectrophotometrically at 546 nm. A volume fraction of 40% N,N-dimethylformamide (DMF) greatly enhances the selectivity of the method. The chemical (pH and concentrations of reagents) and instrumental variables (sample injection volume, reagents flow rates, reaction coil length) affecting the determination were studied and optimized. Under the selected values, the analyte could be determined in the range of 0.1–12.0 mg L−1 (r = 0.9997), at a sampling rate of 120 h−1. The proposed assay was precise (sr = 0.8% at 5.0 mg L−1 Au(III), n = 12) and adequately sensitive with a 3σ limit of detection of 0.03 mg L−1. The method was successfully applied to the analysis of jewel samples. The obtained results were favorably compared to flame atomic absorption spectrometry (FAAS) used as a reference method.
Journal: Talanta - Volume 72, Issue 1, 15 April 2007, Pages 277–281