title: Internal standardization combined with dilute-and-shoot preparation of distilled alcoholic beverages for Cu determination by high-resolution continuum source flame atomic absorption spectrometry.
abstract: 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 A(Cu)/A(Bi) and A(Cu)/A(Te)versus Cu concentration (0.05-4.0 mg L(-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 0.029-3.608 mg L(-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. 5 μg L(-1) using Bi or Te.
authors.affiliation: Universidade Federal da Grande Dourados, Faculdade de Ciências Exatas e Tecnologia, 79804-970 Dourados, MS, Brazil.
authors.forename: Jorge Luiz
authors.initials: JL
authors.lastname: Raposo
authors.forename: Adriana Paiva
authors.initials: AP
authors.lastname: de Oliveira
authors.forename: Bradley Todd
authors.initials: BT
authors.lastname: Jones
authors.forename: José Anchieta
authors.initials: JA
authors.lastname: Gomes Neto
mesh_terms: D000434:Alcoholic Beverages / Q000032:analysis* / Q000592:standards; D001729:Bismuth / Q000032:analysis; D002138:Calibration; D003300:Copper / Q000032:analysis*; D000431:Ethanol; D005504:Food Analysis; D057230:Limit of Detection; D012015:Reference Standards; D013054:Spectrophotometry, Atomic; D013691:Tellurium / Q000032:analysis
chemical_list: D000431:Ethanol; D003300:Copper; D013691:Tellurium; D001729:Bismuth