Internal standardization combined with dilute-and-shoot preparation of distilled alcoholic beverages for Cu determination by high-resolution continuum source flame atomic absorption spectrometry

• Published in: Talanta (Oxford) 2012-04, Vol.92, p.53-57
• Main Authors: Raposo, Jorge Luiz, de Oliveira, Adriana Paiva, Jones, Bradley Todd, Neto, José Anchieta Gomes
• Format: Article
• Language: English
• Subjects: Alcoholic Beverages - analysis; Alcoholic Beverages - standards; Analytical chemistry; Bismuth - analysis; Calibration; Chemistry; Copper; Copper - analysis; Distilled alcoholic beverages; Ethanol; Exact sciences and technology; Food Analysis; HR-CS FAAS; Internal standardization; Limit of Detection; Reference Standards; Spectrometric and optical methods; Spectrophotometry, Atomic; Tellurium - analysis
• ISSN: 0039-9140; 1873-3573
• DOI: 10.1016/j.talanta.2012.01.035

► Bismuth, In, Sn and Te were evaluated as internal standards for Cu in distilled beverages. ► Bismuth and Te were effective internal standards. ► Dilute-and-shoot sample procedure allowed direct analysis. ► Copper was accurately determined in 22 distilled alcoholic beverages by HR-CS FAAS. Internal standardization (IS) and dilute-and-shoot preparation of distilled alcoholic beverages were evaluated for the direct determination of Cu by high-resolution continuum source flame atomic absorption spectrometry. Among Bi, In, Sn and Te evaluated as internal standards, Bi and Te furnished best results. Calibration curves were built up by plotting ACu/ABi and ACu/ATeversus Cu concentration (0.05–4.0mgL−1) and linear correlation coefficients were 0.9994 and 0.9990, respectively. Contents of Cu in 22 commercial distilled beverages analyzed by the proposed method varied in the 0.029–3.608mgL−1 interval. These results were in agreement (paired t-test) at 95% confidence level with those obtained by line source FAAS using standard addition calibration. Recoveries improved from 77–83% (without IS) to 99–101% (with IS) intervals. The relative standard deviation (n=12) was 0.8–3.7% (IS-Bi), 0.4–4.4% (IS-Te), and 0.5–9.1% (without IS) and the limit of detection was ca. 5μgL−1 using Bi or Te.