Determination of Cu(II) in Beer by Derivative Potentiometric Stripping Analysis
Heidi Mayer 1, Ombretta Marconi 1, 2,
Simona Floridi 1, Luigi Montanari1 and Paolo Fantozzi 1
1 Centro di Eccellenza per la Ricerca sulla Birra (CERB) (Italian Brewing Research Centre), Faculty of Agriculture, University
of Perugia, via S. Costanzo 06126 Perugia, Italy.
2 Corresponding author. Email. omarconi@unipg.it
J. Inst. Brew. 109(4), 332-336, 2003 | VIEW ARTICLE
ABSTRACT
Derivative Potentiometric-Stripping Analysis (dPSA) is described as an inexpensive and rapid method for the determination of Cu(II) in beer. Beer samples were analysed directly after degassing and addition of the analytical reagents (hydrochloric acid, mercury(II) chloride, and potassium metabisulfite). It was not necessary to digest the sample. During dPSA the metal ions are deposited on a glassy carbon-working electrode and then stripped by a suitable oxidant. Quantitative analysis was carried out by the method of standard additions. The recovery of the method was tested by adding 50 µg L -1, 75 µg L -1 and 100 µg L -1 of Cu(II) (as Cu(II) chloride solution) to the beer. The mean recoveries of Cu(II) ranged from 95 ± 5% to 98 ± 2%. The reproducibility was evaluated by three repetitive analyses for each sample and the standard deviation ranged from 0.6 µg L -1 to 5.5 µg L -1. The detection limit was 0.8 µg L -1. The Cu(II) concentration determined in seven beer samples ranged from 28 µg L -1 to 48 µg L -1 and the results obtained were not significantly different from those obtained by atomic absorption spectrophotometry (AAS).
Key words:
Beer, copper, derivative potentiometric stripping analysis.
Publication no. G-2003-1222-169 ©2003 The Institute & Guild of Brewing