Fast and direct screening of copper in micro-volumes of distilled alcoholic beverages by high-resolution continuum source graphite furnace atomic absorption spectrometry

• Published in: Food chemistry 2016-12, Vol.213, p.799-805
• Main Authors: Ajtony, Zsolt, Laczai, Nikoletta, Dravecz, Gabriella, Szoboszlai, Norbert, Marosi, Áron, Marlok, Bence, Streli, Christina, Bencs, László
• Format: Article
• Language: English
• Subjects: Alcoholic Beverages - analysis; Calibration; Calibration methods; Copper - analysis; Distilled alcoholic beverages; Electrothermal atomic absorption spectrometry; Food Analysis; Graphite; Graphite furnace electrothermal vaporization; Heavy metal content; Limit of Detection; Rapid furnace program; Spectrophotometry, Atomic
• ISSN: 0308-8146; 1873-7072
• DOI: 10.1016/j.foodchem.2016.06.090

•Cu is quantitated by HR-CS-GFAAS via directly dispensing microliters of samples.•Alternative Cu line (249.2146nm) & adjacent lines of internal standards were used.•Fast & regular GF-heating programs without & with Pd modifier were optimized.•Pyrolysis & atomization curves were recorded for Au, Cu, Cr, Fe, Na, Os and Rh.•External & internal calibration was used for analyzing ∼40 distilled beverages. HR-CS-GFAAS methods were developed for the fast determination of Cu in domestic and commercially available Hungarian distilled alcoholic beverages (called pálinka), in order to decide if their Cu content exceeds the permissible limit, as legislated by the WHO. Some microliters of samples were directly dispensed into the atomizer. Graphite furnace heating programs, effects/amounts of the Pd modifier, alternative wavelengths (e.g., Cu I 249.2146nm), external calibration and internal standardization methods were studied. Applying a fast graphite furnace heating program without any chemical modifier, the Cu content of a sample could be quantitated within 1.5min. The detection limit of the method is 0.03mg/L. Calibration curves are linear up to 10–15mg/L Cu. Spike-recoveries ranged from 89% to 119% with an average of 100.9±8.5%. Internal calibration could be applied with the assistance of Cr, Fe, and/or Rh standards. The accuracy of the GFAAS results was verified by TXRF analyses.