Determination of Ni (II) in Beverages without Any Sample Pretreatment by Adsorptive Stripping Chronopotentiometry (AdSCP)
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- 作者：Giacomo Dugo ; Lara La Pera ; Vincenzo Lo Turco ; Giuseppa Di Bella ; and Francesco Salvo
- 刊名：Journal of Agricultural and Food Chemistry
- 出版年：2004
- 出版时间：April 7, 2004
- 年：2004
- 卷：52
- 期：7
- 页码：1829 - 1834
- 全文大小：97K
- 年卷期：v.52,no.7(April 7, 2004)
- ISSN：1520-5118
文摘
The purpose of this paper was to use adsorptive stripping chronopotentiometry for the determinationof Ni (II) in worldwide consumed beverages without any sample pretreatment, using dimethilglyoxime(DMG) as complexing agent and a glassy carbon mercury film electrode as the working electrode. Ni(DMG)2 complex is adsorbed onto the mercury film at an electrolysis potential of -500 mV for 60 sand then reduced by a -5 
A constant cathodic current. The sensitivity of the method was studiedfor certified reference water and black tea in the pH range 6.5-11. At pH 9.5 in ammonia buffer, adetection limit of 0.2 g L-1 was achieved; the instrumental precision (expressed as rsd %) was1.5%, and the accuracy, expressed as obtained recoveries both from certified and not certifiedmatrixes, ranged from 93.0 to 95.5 %. The chronopotentiometric analysis executed on commercialbeverages provided evidence that black tea samples were the richest source of Ni (II) (1500-3700g L-1), followed by coffee (100.0-300.5 g L-1); bottled mineral water showed a Ni (II) concentrationlower than 4.6 g L-1. Among alcoholic beverages, red wines presented the highest content of Ni (II)(55.5-105.0 g L-1). Significant differences were noticed between Ni (II) levels of fermented anddistillated alcoholic beverages; moreover, canned cola and beer did not show higher Ni (II) levelswith respect to the glass-bottled products.Keywords: Adsorptive stripping chronopotentiometry; beverages; nickel
A constant cathodic current. The sensitivity of the method was studiedfor certified reference water and black tea in the pH range 6.5-11. At pH 9.5 in ammonia buffer, adetection limit of 0.2 g L-1 was achieved; the instrumental precision (expressed as rsd %) was1.5%, and the accuracy, expressed as obtained recoveries both from certified and not certifiedmatrixes, ranged from 93.0 to 95.5 %. The chronopotentiometric analysis executed on commercialbeverages provided evidence that black tea samples were the richest source of Ni (II) (1500-3700g L-1), followed by coffee (100.0-300.5 g L-1); bottled mineral water showed a Ni (II) concentrationlower than 4.6 g L-1. Among alcoholic beverages, red wines presented the highest content of Ni (II)(55.5-105.0 g L-1). Significant differences were noticed between Ni (II) levels of fermented anddistillated alcoholic beverages; moreover, canned cola and beer did not show higher Ni (II) levelswith respect to the glass-bottled products.Keywords: Adsorptive stripping chronopotentiometry; beverages; nickel