A renewable copper electrode as an amperometric flow detector for nitrate determination in mineral water and soft drink samples

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• 作者：Juan C.M. Gamboa ; Roselyn C. Peñ ; a ; Thiago R.L.C. Paix&#xe3 ; o ; Mauro Bertotti
• 关键词：Nitrate ; Nitrite ; Flow injection analysis ; Renewable copper surface ; Mineral water ; Soft drink
• 刊名：Talanta
• 出版年：2009
• 出版时间：15 December 2009
• 年：2009
• 卷：80
• 期：2
• 页码：581-585
• 全文大小：213 K

文摘

A novel approach was developed for nitrate analysis in a FIA configuration with amperometric detection (E = −0.48 V). Sensitive and reproducible current measurements were achieved by using a copper electrode activated with a controlled potential protocol. The response of the FIA amperometric method was linear over the range from 0.1 to 2.5 mmol L⁻¹ nitrate with a detection limit of 4.2 ;c;mol L⁻¹ (S/N = 3). The repeatability of measurements was determined as 4.7 % (n = 9) at the best conditions (flow rate: 3.0 mL min⁻¹, sample volume: 150 ;c;L and nitrate concentration: 0.5 mmol L⁻¹) with a sampling rate of 60 samples h⁻¹. The method was employed for the determination of nitrate in mineral water and soft drink samples and the results were in agreement with those obtained by using a recommended procedure. Studies towards a selective monitoring of nitrite were also performed in samples containing nitrate by carrying out measurements at a less negative potential (−0.20 V).